Automotive Abbreviations 
/MIN Per minute, usually RPM, physical
unit 
°C Degrees Celsius, physical unit 
°DK Degrees
throttle-valve angle, physical unit 
°F Degrees Fahrenheit, physical
unit 
°KW Degrees crankshaft, physical unit 
°NW Degrees
camshaft, physical unit 
1/CM3 1/cm³, per cubic centimeter, unit 

1L Axle 1 (usually front axle), left side 
1R Axle 1 (usually front
axle), right side 
2L Axle 2, left side 
2R Axle 2, right
side 
2WD 2-wheel drive 
3L Axle 3, left side 
3R
Axle 3, right side 
4WAS Four wheel anti skid, traction control system
for four-wheel drive vehicles, refer also to ASR 
4WD 4-wheel
drive 
4WS Four-wheel steering. All 4 wheels are steered, not just the
front wheels. 
4X4 Vehicle with 4 wheels, all of which are driven
(all-wheel drive). See also 4WD. 
A Ampere, physical unit, or
Austria 
A/D Analog/digital, usually A/D converter: converts analog
signals (such as speed or oxygen sensor voltage) to digital signals that can be
processed by a computer 
A1 Axle 1, usually front axle 
A2/3
Axles 2/3, rear axle(s) 
AA Automatically triggered alarm 
AAC
Auxiliary-air control valve 
AAP Acceleration auxiliary pump 

AAS Drive-off assistant 
AAV Activated charcoal filter shutoff
valve 
AB Airbag, usually proper name 
ABC Active body
control, chassis, see also ADS 
ABD Automatic braking differential,
usually proper name 
ABE General operating licence, model approval of
car for operation on public roads 
ABS Anti-Blocking System, usually
proper name 
ABS 2 Anti-Blocking System separate, system name, proper
name 
ABS 3 Anti-Blocking System integrated in brake booster, system
name, proper name 
ABV Auxiliary-air valve or Automatic blocking
prevention, another term for ABS 
AC Air conditioning, air conditioner,
or Alternating current 
ACC Adaptive cruise control 

ACD
ACM Active centre differential, automatic limited-slip differential
(Mitsubishi)
Airbag Control Module
ACT
 Air charge temperature.
Temperature of charge air with turbocharger.
 
ADA
Atmospheric-pressure dependent full-load stop with distributor injection
pumps 
ADAM Advanced dynamic aid mechanism, mechanical braking
assistant (Teves). See also BAS. 
ADAPT Adaptation, adaption 

ADB Automatic differential brake. BMW system replacing conventional
limited-slip differentials (ensures traction by braking wheels). Subfunction of
DSC (BMW ESP). 
ADF Atmospheric pressure sensor 
ADN
Yemen 
ADR Automatic distance control, proper name (VW), or Trigger
duration control 
ADS Automatic throttle-valve actuator or Active
driving system or Adaptive damping system 
AEI Advance electronic
ignition, fully electronic ignition system 
AEU Outside Europe 

AFB Atmospheric-pressure dependent start-of-delivery 
AFI
Air-supported fuel injection 
AFS Advanced front-lighting system.
Variable light distribution via movable reflectors 
AG Automatic
transmission 
AGN Exhaust-gas aftertreatment 
AGR Exhaust-gas
recirculation 
AGRV Exhaust-gas recirculation valve 

AHK
AHM Trailer coupling, or Active rear-axle kinematics
Auxilliary
Heater Module
AHS Alcohol sensor 
AHV Trailer brake valve 

AI Air injection 
AICC Autonomous intelligent cruise control (speed
and distance) 
AIV Air injection valve 
AK Automatic clutch.
Clutch operates when driving off, shifting, and stopping. 
AKEK
Automatic child-seat detection, usually integrated into an airbag system 

AKF Activated charcoal filter 
AKS Automatic clutch system. Clutch
engagement/disengagement is automatic. The clutch pedal is no longer needed.
Used for example in Renault Twingo; see also EKS, or Active headrest system
(BMW) 
AKSE Automatic child-seat detection 
AKT Active, or
Current 
ALB Automatic load-dependent braking force control 

ALC Adaptive light control. The headlight illumination is distributed
variably according to the driving situation (city, country, motorway).
(BMW) 
ALDA Absolute measurement, boost-pressure dependent full-load
stop 
ALDL Assembly Line Diagnostic Link, Opel diagnostic plug 

ALFB Atmospheric pressure and load-dependent start-of-delivery 
ALG
Axle load sensor 
ALR Automatic longitudinal control 
ALU
Arithmetic and logic unit (microcomputer), proper name 
ALV Axle load
distribution (drive-off aid) 
ALWR Automatic headlight vertical aim
control 
AM Central America 
AMIC Automotive Multimedia
Interface Collaboration, Gremium zur Entwicklung eines Multimediastandards,
besteht im wesentlichen aus führenden Automobilherstellern 
AMR Drive
torque control 
ANC Active noise control. System actively influences
the intake noise, reducing it by about 15 dB. 
AND
AOS Logical AND
operator
Automatic Ocupant Sensing
AP Air pump 
APB Active
parking brake. Teves system containing interface to electronics, with
driver-assistance functions such as drive-off assistance, parking aid, and
immobilizer. 
APS Autopilot system 
ARA Anti-jerking
control 
ARD Active jerking suppression 
ARF Exhaust-gas
recirculation 
ARFR Exhaust-gas recirculation rate 
ARMADA
Triggering unit for restraint systems with external differentiated triggering.
Airbag system from DaimlerChrysler. 
ARMIN Trigger unit for restraint
systems with integrated emergency-call control 
ARR Exhaust-gas
recirculation control 
ART Distance-based cruise control 
AS
Air intake or Towing protection or South America 
ASC Automatic
stability control, controlled force transmission 
ASC+T Automatic
stability control, regulated force transmission with traction control 

ASD Automatic limited-slip differential, usually proper name 
ASF
Audi Space Frame, special construction for aluminium frame in Audi A2 and
A8 
ASG Attachment control unit or Semi-automatic transmission 

ASM
ASM Asynchronous machine
Alarm Siren Module
ASMS Automatic
stability management system. See also ESP. 
AS-NO Exhaust-gas sensor
for NOx (nitrogen oxide) content 
ASP Shutoff valve for ASR brake
control 
ASR Transmission slip control, usually proper name 

ASR 2 Transmission slip control, separate, system name, proper name 

ASR 3 Transmission slip control, integrated, system name, proper name 

AS-T Exhaust-gas sensor for temperature 
ASV Air switching valve,
air intake valve or Trailer control valve 
AT Automatic
transmission 
ATB Exhaust-gas temperature limitation 
ATF
Exhaust-gas temperature sensor or Automatic transmission fluid 
ATG
Replacement transmission 
ATL Exhaust-gas turbocharger 
ATWS
Anti-theft warning system (Opel) 
AU Exhaust-gas inspection 

AUS
AUS Australia
Ultrasonic Alarm System
AUT Automatic
transmission 
AV Outlet valve or Shutoff valve 
AW Drive
shaft 
AWG Evaluation switching unit 
AWK Spare piston, used
if proper piston does not function 
AWN ASA Workshop Network, proper
name 
AWR Distance warning radar 
AWS Evaluation switching
unit (Bosch KH) 
AY Lateral acceleration. A=acceleration, Y=lateral
direction 
AYC Active yaw control. Rear-axle limited-slip differential
(Mitsubishi). See also ACD. 
AZG Adaptive cylinder equalisation.
Quantity equalisation control. 
B Internal combustion engine (petrol)
or Bank or Belgium 
B- Battery negative voltage 
B.C.D.D.
Vacuum controlled idle air correction 
B.P.T. Pressure control
valve 
B+ Battery positive voltage 
BA Acceleration sensor or
Brake assistant (Mercedes Benz) 
BAR bar, physical unit 
BAS
Brake assistant system 
BBA Service brake system. Enables the driver to
reduce the speed of a vehicle in steps during operation (including to
standstill). In addition to the service brake system, a vehicle can have a
parking brake, a retarder system, or an auxiliary braking system. A service
brake system can be a single- or multiple-circuit system and can work
mechanically, hydraulically, or pneumatically. 
BBR
BBUS Wideband
noise test, method for testing potentiometers
Body Bus
BBV Service-brake
valve. Component of service brake system. See also BBA. 
BC Blink
code 
BCM Body control module (Opel and GM) 
BD Bd: baud. Unit
for data transmission rate. 1 baud is 1 bit/second. 
BDE Petrol direct
injection 
BDM Petrol/diesel speed measurement module 
BEA
Bosch Emissions Analysis, product name for exhaust-gas tester (Bosch) 

BEV Battery electric vehicle 
BF Passenger, or passenger-side 

BFA Passenger airbag. See also BF-AB. 
BF-AB Passenger airbag 

BFL Brake fluid level 
BFS Passenger side 
BG Brake
assembly, integrated ABS, or Bulgaria 
BHKZ Battery high voltage
capacitor ignition 
BIP Start pulse 
BKL Brake indicator
light 
BKR Braking force control 
BKU Braking force
support 
BKV Power brakes 
BLDC Brushless direct current
motor 
BLS Brake light switch 
BLU Brake light suppression.
Activated when the brake assistant carries out a "preliminary charge". The main
brake cylinder is actuated, leading to actuation of the light switch. Since the
driver has not braked, switch-on of the brake light must be suppressed 

BM Reference mark 
BMR Braking torque control 
BOU Brake
operating unit, controls and activates the brakes 
BPA Start of
paraffin precipitation. Also called cloud point. Temperature at which paraffin
crystals precipitate out of diesel fuel. 
BPS Brake test stand 

BR Brake control for ASR or Brazil 
BRP Wideband noise test, method
for testing potentiometers 
BS Brake disc or Acceleration sensor 

BSA Brake system analysis, product name for brake test stand (Bosch) 

BSU Special brake inspection 
BT Brake drum 
BTC Bosch
traffic controller, traffic monitoring system 
BTS Battery disconnect
switch (Mercedes) 
BV Brake valve 
BVA Brake wear
indicator 
BVSV Bimetallic-controlled vacuum switching valve or
Bimetallic vacuum switching valve 
BWN Bosch Workshop Network, proper
name 
BZ Brake cylinder 
BZM Reference mark 
BZW
respectively, or, and/or 
C Capacitor, capacitance, or Chassis (OBD
error codes, for example) or Cuba 
C.R. Compression ratio 

C3/B7 C3/B7 signal (speed signal for trip recorder) 
CAA Clean Air
Act (US exhaust-gas regulations) 
CAL California 
CAN
CANDI
Controller Area Network, mini-network for exchanging data between computers,
proper name
Can Diagnostic Interface
CAN-H CAN High. One of the two data
lines in the CAN bus system. See also CAN. 
CAN-HI CAN High. One of the
two data lines in the CAN bus system. See also CAN. 
CAN-L CAN Low. One
of the two data lines in the CAN bus system. See also CAN. 
CAN-LO CAN
Low. One of the two data lines in the CAN bus system. See also CAN. 

CARB California Air Resources Board (US air-pollution authority), proper
name 
CARIN Autopilot system, Mercedes 
CAS
CAS Computer
aided service, proper name
Collision Avoidance
CAT Catalytic
converter 
CB Vacuum control of starting mixture 
CBC
Cornering brake control 
CC
 Cruise control. See also ACC 

CCM really ccm or cm³, cubic centimeters, unit of volume 
CCW
Counter clockwise, e.g. for indicating direction of rotation of engine 

CD
CDCR Compact disc
Compact Disc Changer Rear
CDI Common Rail
direct injection (in Mercedes and MCC) 
CDL Central door locking,
central locking system limited to doors (Opel) 
CDN Canada 

CELIS Central lighting system (Hella) 
CEM Centralised Electronic
Module (Volvo) 


CFG
Configuration 
CFI
CFPP Cylinder-individual injection
system, proper name
Cold filter plugging point (for diesels)
CGI
Stratified charge gasoline injection, petrol direct injection with stratified
charge through throttle valve and with compressor charging (Mercedes) 

CH Hydrocarbon (normally HC). In conjunction with exhaust-gas systems, HC is
understood to be the portion of unburned fuel in the exhaust, or Switzerland
(Confoederatio Helvetica) 
CH4 Methane, main component of natural gas
(90%), compressed as fuel for natural-gas-powered cars. See also CNG 

CI Ivory Coast 
CID
CID Camshaft identification (position)
sensor
Colour Info Display
CIFI
CIM Cylinder-individual fuel
injection, usually proper name
Column Intergration Module
CIN
Calibration identification number. Part of OBD, consists of 3 letters and at
most 12 digits. Can indicate hardware level, for example. 
CKP
Crankshaft positioning sensor 
CMH Mixture preheating 
CMP
Camshaft positioning sensor 
CNG Compressed natural gas, fuel for
vehicles with gas-powered engines 
CNS Combustion noise sensor,
measures combustion noises (knock sensor) 
CO Carbon monoxide.
Poisonous gas present in exhaust gas. Produced during combustion of carbon with
insufficient oxygen, or Colombia 
CO2 Carbon dioxide, non-poisonous gas
produced during combustion, also known as greenhouse gas 
COMAND
Cockpit management and data systems. System for data exchange and driver
information management. 
CPS Camshaft position/speed sensor /
Crankshaft position sensor
CPU Central processing unit
(microprocessor) 
CPV Constant pressure valve 
CPX CPx:
high-pressure pump of a Common Rail diesel system, such as CP2. It is used in
commercial vehicles. 
CR Common Rail. See CRS. 
CRC Cyclic
redundancy check. Method for generating a checksum, proper name 
CRI
Common Rail injector. Injector of a Common Rail system, comparable to the
injection valve of a conventional injection system. 
CRIN Car radio
identification number 
CRP Common Rail pump. Special high-pressure pump
for the Common Rail system, or Car phone (Opel) 
CRS Common Rail
system. Special diesel direct-injection system in which the fuel is distributed
to the injectors via a common line (Common Rail) under high pressure. 

CRT Master computer or Continuous catalytic converter regeneration by burn
off at 300°C with after-injection 
CRW Common Rail parameters (also
CR-W) 
CS Crankshaft 
CSCV RPM control valve 
CTG CAN
tester (Mercedes) 
CTS Cooling temperature sensor,
Kühlmittel-Temperatursensor 
CTX Continuously variable transaxle 

CV Check valve, shutoff valve, throttling non-return valve 
CVN
Calibration verification number. Part of OBD, contains the checksums for
parameter settings, for example. 
CVT Continuously variable
transmission 
CW Drag coefficient, characteristic value for
aerodynamics or drag, determines drag together with frontal area of vehicle or
clockwise, e.g. for indicating direction of rotation of engine 
CZ
Czech Republic 
D Diesel engine or Decimal number or Drive (position of
automatic-transmission selector lever) or Germany 
D3 German
exhaust-gas standard, parallel to European standard. Corresponds largely to EU3.
See EU3 and EURO3. 
D4 German exhaust-gas standard, parallel to
European standard. Corresponds largely to EU4. See EU4 and EURO4. 
DA
Boost pressure dependent full-load stop 
DAB Digital audio
broadcasting 
DBC Dynamic brake control 
DBE Roof operating
unit, control unit in Mercedes, usually proper name 
DBG Flow
limiter 
DBR Retarder (sustained action brake) or Retarder relay 

DBV Pressure limiting valve 
DC Direct current or
DaimlerChrysler 
DCU Diesel control unit or Dosing control unit. Unit
for injection of urea (serves to reduce NOx). 
DD Fuel pressure
limiter 
DDA Digital directional antenna, special antenna which blocks
out radio wave reflection interference 
DDE Digital Diesel Electronics,
system name, usually proper name, or Direct data exchange 
DDM


DDM Engine speed versus alternator residual ripple or driver door module
(Opel)


Drivers Door Module
DDS Diesel theft protection 
DECT Digital
enhanced cordless telecommunications, standard for data transmission, usually
proper name 
DEE Digital engine electronics 
DF RPM sensor, or
Pressure sensor, or Direct-fire, distributorless coil ignition with double
ignition coil 
DFA Speed sensor output 
DFB Flow limiter
(Common Rail) or Dynamic start-of-delivery setting 
DFC Deceleration
fuel control 
DFHL Speed sensor, left rear 
DFHR Speed sensor,
right rear 
DFM Dynamo field monitor. Output for recording dynamo
field 
DFS Double-spark coil, supplies two cylinders 
DFVL
Speed sensor, left front 
DFVR Speed sensor, right front 
DG
Speed sensor, or Speed sensor for transmission input speed 
DGI Direct
gasoline injection 
DHK Nozzle holder combination 
DI Direct
(diesel) injection, system name, usually proper name 
DI/DIST
Distributor type 
DIA Diagnosis 
DIAGK Diagnosis K line,
communication line 
DIAGL Diagnosis L line, signalling line 

DIGI Digiplex (Marelli) 
DIGIJET Digitally controlled fuel
injection, system name, proper name 
DIGIPLEX Fully electronic ignition
system, system name, proper name 
DIGNITION Electronic ignition system,
system name, proper name 
DIN German Industrial Standard 
DIO
Data input/output. Interface for exchanging data in both directions. 

DIS Direct ignition system, proper name 
DISA Differential intake
manifold system (switchable, variable-length intake manifold) 
DK
Throttle valve or Denmark 
DKA Throttle valve actuator, Ecotronic 

DKE Throttle valve incrementation bit 
DKG Throttle valve sensor,
detects current position of throttle 
DKI Throttle valve actual value.
Current throttle-valve voltage 
DKP Throttle valve potentiometer 

DKR Throttle valve reduction or Throttle valve reduction bit 
DKS
Throttle valve switch 
DKV Throttle valve preset 
DLB
Compressed-air brake 
DLC Data link connector. Diagnosis
connection 
DLI Distributorless ignition 
DLK Dynamic steering
correction 
DLOC Device location, Einbaulage einer Komponente 

DLS Digital idle stabilisation 
DLWR Dynamic headlight vertical aim
control 
DM dm: decimeter DM: Diagnosis module 
DM3/H dm³/H:
cubic decimeters per stroke, unit 
DME Digital Motor Electronics
(Motronic), system name, proper name 
DMM Digital multimeter 

DMS Elongation measurement sensor 
DMV Diesel solenoid valve 

DOHC Double overhead camshaft, usually part of engine designation 

DP Dashpot, or Throttle valve closing damper 
DPF Diesel particle
filter 
DPFE Delta pressure feedback electronic system or Differential
pressure feedback, EGR 
DPHI dphi, delta phi, difference angle. See
also PHI. 
DQ dQ: delta quantity, difference quantity. See also
Q. 
DR Pressure regulator 
DRM Pressure regulator module 

DRS Rotation rate sensor, sensor for vehicle dynamics control 
DRV
Pressure regulator valve 
DS Pressure switch or Pressure sensor 

DSA Dynamic stability assistance 
DSB Pressure sensor in/for
combustion chamber 
DSC Dynamic stability control 
DSE
Thermal-expansion material element, expands or contracts when heated 

DSG
DSM RPM target value sensor
Drivers Seat Module
DSP Display,
or Dynamic shift program (automatic transmission), or Digital sound package (VW
audio equipment variant), or Digital sound processor, special processor for
digital processing of audio signals 
DSS Pressure-jump switch 

DSTC Dynamic stability and traction control 
DSU Pressure sensor
for ambient pressure 
DSV Pressure control valve 
DTC
Diagnostic trouble code 
DTI Diesel direct-injection with distributor
pump (Opel) 
DTR Distronic. Distance control system (Mercedes) 

DV Pressure supply, or Throttle device 
DVD Digital versatile disc.
Storage medium with significantly higher storage capacity than a conventional
CD. 
DVH Pressure valve holder 
DWA Theft warning system,
BMW-specific designation 
DWS Rotation angle sensor 
DYN
Dynamic 
DZ Breakthrough ignition or Algeria 
DZG RPM
sensor 
DZV Digital ignition, fully electronic 
E Electrical
fan, or Fuel-injection engine, or Economy (shifting program for automatic
transmissions), or Spain (España) 
EA Original equipment 
EAG
Electronic automatic transmission 
EAI Electronic advanced ignition,
electronic ignition-curve control, ELZ 
EAK Kenya 
EAS
Electronically autonomous starting system or electronic actuation system,
usually trade name or electronic air suspension (VAG) 
EAV Element
shutoff valve. Shuts off an individual element of the high-pressure pump in the
Common Rail system. 
EBC Electronic brake force control (see EBD and
EBV) 
EBCV Electrical auxiliary air control valve 
EBD
Electronic braking differential or Electronic brake force distribution (see also
EBC and EBV) 
EBM Electronic brake management system. Optimises driving
stability, traction, and braking function (BMW) 
EBS Electronic braking
system 
EBV Electronic brake force distribution (see also EBD and
EBC) 
EC Ecuador 
ECABS Electronic air cushioning, combined
with ABS 
ECC Electronic climate control, electronically controlled air
conditioner (Opel) 
ECD Electronically controlled deceleration 

ECE Economic Commission of Europe, proper name 
ECI Electronically
Controlled Injection, system name, usually proper name 
ECM Electronic
Control Module, system name, usually proper name 
ECO Ecotronic, system
name, usually proper name 
ECON ECOn: Electronic carburetor, n=version,
usually proper name 
ECONZ ECOnZ: Electronic carburetor and electronic
ignition, n=version number, usually proper name 
ECT Engine coolant
temperature, or temperature sensor 
ECU Electronic control unit, proper
name 
EDC Electronic diesel control, usually proper name 
EDG
Electronic diesel control with integrated transmission control. MCC control
unit, proper name. 
EDIS Electronic documentation and information
system (Bosch) 
EDIS 4 EEC IV with distributorless ignition system
(Ford) 
EDR Electronic diesel control NFZ-DB 
EDS Electronic
differential lock, usually proper name 
EDW Electronic anti-theft
warning system or Electronic pressure transducer 
EEC Fully electronic
engine control or Electronic ignition timing, proper name 
EEC IV
Electronic engine control system IV (Ford), system name, proper name 

EECS Fuel vapour emission control system 
EEM Electrical energy
management. Higher-order system that coordinates the interaction of the
generator, battery, voltage converter, drive train, and loads. See also EES and
VSC. 
EEPROM Electrically erasable programmable read-only memory,
proper name 
EES Electrically unlocked starting quantity, or Electrical
energy systems (onboard network of the future (42V generator for electromagnetic
valves, for example, 14V DCDC converter for rest of network) 
EFI
Electronic fuel injection, usually proper name 
EFP Electronic
accelerator pedal, proper name 
EFS Single-spark coil, supplying one
cylinder 
EGAS Electronic accelerator pedal, proper name (electronic
throttle control, ETC) 
EGD Electronically regulated shock
absorption 
EGE Electronic air dryer unit 
EGN EGn: EGAS
control unit, n=version, usually proper name 
EGO Exhaust Gas Oxygen
Sensor, unbeheizte Lambdasonde 
EGR Exhaust gas recirculation 

EGS Electronic transmission control 
EHA Electronic automatic
heater, usually proper name 
EHAB Electrohydraulic shutoff 

EHB Electrohydraulic brake 
EHCM Electrohydraulic control
module 
EHPS Electrohydraulic power steering 
EHR
Electrohydraulic lifting control 
EHS


EHU Electrohydraulic control module


Entertainment Head Unit
EHSW Electrohydraulic positioner 
EI
Electronic ignition 
EKE Electronic fuel injection, proper name 

EKM Electronic clutch management 
EKP Electric fuel pump 

EKRG Simple short-circuit ring sensor 
EKS Electronic clutch
system. Clutch engagement and disengagement is automatic. The clutch pedal is no
longer needed. See also AKS. 
ELAB Electrical idle shutoff valve 

ELB Electronically controlled brake 
ELD Electrical load-peak
damping 
ELF Electronic air cushioning 
ELFI Electronic
vehicle identification. Component of VW ELSA service information system. 

ELR Electrical ignition system with ignition curve adjustment or Electronic
idle control 
ELRA Electronic automatic restraint. Automatic seat belts
(VW) 
ELS Electronic idle stabilisation 
ELSA Electronic
service information system. VW system for authorised workshops (garages).
Comprises the components ELFI, ELWIS, and ETKA. 
ELV Electrical air
valve, or Electronic steering or steering-column lock. See also ESL. 

EL-V Electronically controlled carburetor 
ELWIS Electronic shop
information system. Component of the VW ELSA service information system. 

ELZ Electronic ignition 
EMAB Shutoff by electromotor 
EMB
Electromechanical brake 
EMC Electromagnetic compatibility (see also
EMV) 
EMF Electromechanical parking brake. 
EMI Injection
volume indicator 
EML Electronic engine performance control, proper
name 
EMR Electronic volume reduction 
EMS Electronic engine
control, proper name 
EMSE Electromagnetic start enable 
EMV
Electromagnetic compatibility (EMC) 
ENG Engine type (code letters), or
Engine 
ENG FAIL Engine failures, diagnosis line for outputting
errors 
ENR Electronic level control 
EOBD European on-board
diagnosis, internal vehicle diagnosis with external tester conforming to
European guidelines. Serves primarily to record exhaust-gas related faults.
Usually trade name 
EOL End of line, usually in conjunction with
end-of-line programming 
EP Adjustment point 
EPA
Environmental Protection Agency, air purity monitoring organisation 

EPAS Electric power-assisted steering 
EPB


EPB Electropneumatic brake


Electronic Park Brake
EPC Electronic power control or Electronic pedal
control (such as with ME-Motronic systems without mechanical throttle
cable) 
EPI Exhaust Port Injection, Nacheinspritzung in Auslasskanal
(Toyota) 
EPK Electropneumatic kit 
EPROM Erasable
programmable read-only memory, programmable or erasable with UV light, proper
name 
EPS Extended park position, or Injection pump test bench,
sometimes used as a product identification (such as EPS 944) 
EPSV
Electrical injection adjustment 
EPT Electronic pressure
transmission 
EPW Electro-pneumatic transducer, serves to transform
electrical signals into pneumatic signals such as in boost-pressure
regulation 
ER Energy reserve 
ERE Electronic inline injection
system (special engine control) or Electrical regulator 
ERW Energy
reserve with voltage converter 
ERWIN Electronic repair and workshop
information. VW electronic service information system for independent workshops
(garages) and fleet operators. Information offering is restricted compared to
ELSA. 
ES Electronic control unit or El Salvador 
ESA
Emissions system analysis, product name for exhaust-gas tester (Bosch) or
Electronic spark advance 
ESA/IZA Map ignition, ignition coil in
distributor 
ESC Escape key on PC or Map ignition or Electronic spark
control, electronic ignition control up to knock region, with knock sensor 

ESG Single-pane safety glass or Electronic switching unit for trailer
detection (used in brake systems) 
ESGN ESGn: Special equipment, e.g.,
NWS, ETS, KGE, n=version no. 
ESL Electronic steering lock. See also
ELV. 
ESP Electronic stability program, another designation for
vehicle-dynamics control (FDR), usually proper name 
ESPV Electrical
injection adjustment 
ESR Electronic slip reduction, another name for
ASR, or Electrical sunroof, electrically operated sunroof (or lifting
roof) 
ESS Electronic suspension systems. Continental Teves electronic
air cushioning system. The system adapts automatically to vehicle load
conditions, has continuously variable damping, and works together with
ESP. 
ESSD Electrical steel sunroof 
EST Electronic spark
timing, electronic map ignition control. See also MSTS 
ESV Feed valve
or Injection valve 
ET Egypt 
ETC Electronic throttle control,
usually proper name or Electronic traction control 
ETKA Electronic
parts catalogue. Component of the VW ELSA service information system. 

ETM Electronic transmission management, usually proper name 
ETS
Electronic thermostat control, usually proper name or Electronic traction
system, see ETC 
ETV Electronic throttle valve 
EU European
Union 
EU3 European exhaust-gas standard, valid from 2000 (levels: HC
0.2, CO 2.3, NOx 0.15) 
EU4 European exhaust-gas standard, valid from
2005 (levels: HC 0.1, CO 1.0, NOx 0.08) 
EUI Electronic unit injector,
injection nozzle of pump-nozzle system (diesel injection) 
EUP
Electronic unit pump, diesel pump of pump line nozzle system (diesel
injection) 
EURO3 European exhaust-gas standard, valid from 2000
(levels: HC 0.2, CO 2.3, NOx 0.15) 
EURO4 European exhaust-gas
standard, valid from 2005 (levels: HC 0.1, CO 1.0, NOx 0.08) 
EUV
Electro-reversing valve 
EV Injection valve or Inlet valve of pressure
control valve or Inlet valve of ABS system 
EV1 Injection valve for
high pressure 
EV2 Injection valve for low pressure 
EVA
Electrical full-load stop or Emergency valve assistance, safety valve 

EVAP Fuel vapor emission control 
EVE Electronic distributor
injection system (special engine control) 
EVR Electronic vacuum
regulator 
EWD Single-coil actuator, servomotor with one winding 

EWL External warning lamp 
EWM Electronic selector-lever module.
Control unit in Mercedes, usually proper name 
EWMA Exponential
weighted moving average, misfire detection during last 10 driving cycles 

EWS Electronic immobilizer 
EX Exhaust (or outlet, exhaust-gas
recirc. valve, exhaust manifold) 
EZ Electronic ignition, usually
proper name 
EZE Electronic central control unit, usually proper
name 
EZF Electronic ignition system, map-controlled 
EZF-H
Electronic ignition system with map, trigger by Hall sensor 
EZF-I
Electronic ignition system with map, trigger by inductive sensor 
EZK
Electronic ignition with knock control 
EZ-K Electronic ignition timing
with knock controls, proper name 
EZL Electronic ignition system with
characteristic curves 
EZL-H Electronic ignition with characteristic
curves, trigger by Hall sensor 
EZS Electronic ignition switch 

EZV Electronic ignition timing 
F France 
F/P Fuel
pump 
FA Front axle 
FAB Failcode Airbag. Output line for
error codes for airbag system (Mazda) 
FAC Failcode Air Conditioning.
Output line for error codes for air conditioner (Mazda) 
FAP
Accelerator pedal or Vehicle analysis protocol. Log maintained by tester during
diagnosis. Can be printed and given to vehicle owner as evidence of repairs
performed.. 
FAS Driver-assistance system 
FAT Failcode
Automatic Transmission. Output line for error codes for transmission control
(Mazda) 
FB Fast burn, rapid spread of flame front or
Start-of-delivery, key parameter in diesel injection systems or Remote
control 
FBA Parking-brake system (usually hand brake) 
FBB
Start-of-delivery blocking 
FBG Start-of-delivery sensor 
FBKW
Crankshaft angle at start-of-delivery 
FBN Start of delivery,
normal 
FBR Start-of-delivery control 
FBS Driving enabling
system (Mercedes), or Failcode Brake System. Output line for error codes for ABS
system (Mazda) 
FBV Parking brake valve 
FC Fault (error)
code 
FCKW Chlorofluorocarbon (CFC). Gaseous chemical compound that
destroys the ozone layer. Contained in old refrigerants (R12) for air
conditioners. 
FCV Fuel cell vehicle. Vehicle with fuel-cell drive, up
to now only a Ford prototype. 
FD Date of manufacture 
FDI
Fuel direct injection, gasoline direct injection, refer also to GDI 

FDR Trip computer or Vehicle dynamics control 
FDS Ford diagnostic
system 
FE
FEC Delivery units, parameter for determining delivered
fuel amount
Front Electrical Centre
FEN Failcode Engine. Output line for
error codes for engine control unit (Mazda) 
FES Spark energy
control 
FFG Accelerator pedal 
FFR Vehicle master computer.
Diagnostic gateway in vehicle, installed in combined instruments or central
electrical system. Also contains the immobilizer. 
FGB/AGB Speed
limiter / automatic speed limiter, usually proper name 
FGB/GBA Speed
limiter / speed limiting system, usually proper name 
FGG Speed
sensor 
FGR Speed control, usually proper name 
FH Power
window 
FHE Road and obstacle detection 
FHM Power window
motor 
FI Filter 
FICD Fast-idle control device 
FIN
Finland 
FIS Vehicle information system. Product designation (such as
FIS 215) 
FJI Fiji Islands 
FKT Function 
FKTSCH
Function switch 
FLA Vehicle performance analysis, product name for
performance test stand (Bosch), or Spring-loaded idle stop 
FM Vehicle
management 
FMN Delivery volume normal 
FMVSS Federal motor
vehicle safety standard 
FN Vehicle level 
FP Accelerator
pedal or Delivery pump 
FPK Freely programmable combined
instruments 
FPM Accelerator pedal module 
FPR Fuel pump
relay 
FR FR signal: provides engine or engine/transmission control
unit with information about generator load. 
FRS Freewheel pulley 

FS Driving-mode switch or Driver side 
FSA Vehicle system analysis,
product name for engine tester (Bosch) 
FSD Folding sunroof 

FSG Chassis control unit or Fill-level sensor 
FSK Frequency shift
keying 
FSR Driving stability control 
FSS Delivery signal
sensor, or Flexible service system 
FTCO Flat tachograph (new, flat
design), Mercedes 
FV Filling valve 
FWA Chassis analysis.
Sometimes also used as product designation (such as FWA 400) 
FWI
Vehicle-travel pulse number 
FZ Vehicle 
FZG Vehicle 

FZK Vane compressor 
FZR Vehicle controller, ESP system
component 
G g: Acceleration of gravity, or gram, physical unit G:
G-signal : crankshaft signal for TDC, 4 signals for the control unit per
distributor rotation 
G/SEC g/sec: grams per second, unit 

G/ZYL g/Zyl: grams per cylinder, unit for mass per cylinder 
GA
Basic adaptation or Guarantee 
GATES Global automotive telematic
standard 
GB Yawing moment restriction or Great Britain 
GBA
Seat belt positioner drive 
GBR Seat belt positioner 
GDB
Regulated differential brake 
GDI Gasoline direct injection,
designation for petrol direct injection systems or vehicle models with this
system. Usually proper name. 
GDL Gas pressure lamp (Audi) 

GDV Constant pressure valve 
GEN Generator 
GER
Germany 
GGF ggf.: possibly, if necessary 
GGS Transmission
group switch 
GHD Housing cover 
GID Graphic information
display (Opel) 
GK Glow plug 
GM Basic module, or Gear motor,
or General Motors, proper name (name of vehicle manufacturer) 
GMA
Yawing moment buildup delay 
GMR Mixture regulator 
GND
Ground 
GOL Persian Gulf states 
GPS Global Positioning
System, satellite system for locating a vehicle 
GR gr: large Gr: Group
GR: Gas retention, or Greece 
GRA Speed control system. Alternative
term for cruise control. 
GRV Constant-volume valve 
GS
Independent electronic transmission control, usually proper name, or Belt
tensioner 
GS 1.2 Electronic transmission control, Version 1.2, system
name, proper name 
GSG Speed sensor 
GSH Gas sensor
hydrocarbon, hydrocarbon sensor 
GSK Sheathed element glow plug 

GSM Global system for mobile communication 
GSR Belt tensioner,
usually proper name 
GSS Transmission shift lock or Seatbelt buckle
switch 
GST Stepped start volume 
GSY Speed symbol.
Specification on tyres for allowable speed, alphabetic. See also Speed
Index 
GUS Belt tensioner or Commonwealth of Independent States
(CIS) 
GW Gateway. PC or computer that connects and controls data
exchange between two networks. 
GWK Transmission converter clutch 

GZS Glow duration control unit 
H h: hours H: hexadecimal number,
or stroke, or Hungary 
HA Hydraulic stop or Rear axle or Hydraulic
modulator for ABS 
HAC Height compensation 
HAI Hot-air
inlet 
HAS Hand brake switch 
HAU Automatic heating 

HBA Hydraulic brake assistant or Hydraulically operated equalisation or
Auxiliary brake system 
HBZ Master brake cylinder 
HC High
compression or Version with high compression ratio or Hydrocarbon 
HD
Heating wire or Lifting roof 
HDC Hill descent control. Special system
that maintains speed downhill. Works using brake intervention at about 5 mph (8
km/h) (BMW and Rover offroad vehicles) 
HDEV High-pressure injection
valve 
HDF Remote boot-lid release 
HDI High-pressure direct
injection 
HDK Half-differential short-circuit ring travel sensor 

HDP High-pressure pump 
HDS Urea metering system, used with diesel
vehicles to prevent or reduce soot emissions 
HE Main injection 

HEGO Heated exhaust-gas oxygen sensor 
HEI High performance
ignition system, transistorized ignition, contactless ignition 
HEV
High-pressure injection valve 
HF High frequency 
HFG
Hand-operated gas delivery, for example in special vehicles for handicapped
drivers 
HFM Hot-film air-mass sensor or Special engine control in
which load detection takes place via a hot-film air-mass sensor 
HH HH
division, 4/4 division of brake circuit: circuits 1 and 2 brake all
wheels. 
HHC Hill Holder Control, ESP system component 
HHT
Hand-held tester (such as KTS500 or PMS100) 
HIC Hot idle
compensation 
HID Hill descent (sensor). Sensor that registers
downgrades or vehicle rolling. See HDC. 
HK Height correction or Hong
Kong 
HKD High-voltage trigger diode, special diode installed in
ignition coils 
HKZ High-voltage capacitor ignition 
HL Left
rear 
HLM Hot-wire air-mass sensor 
HO2S Heated oxygen (O2)
sensor 
HP Hydraulic pump 
HPA hPa: hectopascal, physical
unit 
HPDI High pressure direct injection 
HPI High-pressure
injection. Direct-injection petrol engine used in Citroen and Peugeot.
Comparable with GDI. 
HR Hybrid control, or Right rear, or
Croatia 
HRA Rear window washing system 
HSCAN High-speed
controller area network. CAN bus with high transmission rate (Opel). See also
CAN, LSCAN, and MSCAN. 
HSPV Hydraulic injection timing device 

HSV High-voltage distribution or Hydraulic start lock 
HT HT
division. 4/2 division of brake circuits: circuit 1 brakes all wheels, circuit 2
the front wheels 
HU Major inspection 
HW Hardware 

HYAB Hydraulic shutoff device 
HZ HZ: Master brake cylinder Hz:
hertz, physical unit 
HZR Heating control. Simple type of air
conditioner. 
I Italy 
I1 Incremental system with one
sensor 
I2 Incremental system with two sensors 
IAC Idle air
control, i.e. idle speed control, for injection engines 
IAM
Independent after-market. Service or spare-parts dealers independent of vehicle
manufacturer. 
IC Integrated circuit 
ICC Intelligent cruise
control, Nissan distance control system; see also ACC. 
ICE Ignition
control electronics, electronic ignition system 
ICM
ICM Ignition
control module, or Integrated chassis management, BMW vehicle-dynamics control
with trend-setting technology
Infotainment Module
ID Identifier, bei
CAN-Bus-Systemen eine Art Address-Byte, das angibt, für wen ein Datenblock
bestimmt ist oder Identifikation 
IDI Indirect (diesel) injection 

IDIS Integrated driver information system, similar to navigation
system 
IDS Interactive dynamic driving system 
IFS Inertia
fuel shutoff. Safety fuel shutoff, or Independent front-wheel suspension 

IFZ Infrared central locking 
IG Pulse or increment transmitter, or
Ignition 
IHE Integrated hydroelectronics unit. Control electronics,
hydraulic generator, and electric motor in Citroen Hydraktiv chassis. 

IHKA Integrated heating and air conditioning system (BMW) 
IHR
Heating control, usually proper name 
IIA Integrated ignition
system 
IL Israel 
ILV Integrated quiet-running system 

IMA Integrated engine assistant (special Honda engine control), or Injector
quantity analysis 
IMM Immobilizer 
IMMO Immobilizer 

IMP Pulse(s) 
IN Inlet (intake) manifold or valve 
INA
Information display for ASR systems 
IND India 
INFOANZ
Information display for ASR systems 
INJ Injector. Injection jet or
valve in Common Rail diesel system 
INT Integrator 
INZ


IPBEC Central injection


Instrument Panel Body Electrical Centre
IPS Intelligent Protection
System, integrated two-stage airbag system with retractable pedals,
head/shoulder airbags, and active headrests. Used in Ford Mondeo. 
IR
Individual control with commercial-vehicle ABS systems, or Infrared, or
Iran 
IRF Interior filter 
IRM Individual control, modified,
with commercial-vehicle ABS systems 
IRQ Iraq 
IRS Interior
protection 
IS Iceland 
ISA Idle speed correction or
Intelligent speed adaptation: Use of a GPS system and traffic-sign database to
automatically regulate speed (system still in test phase) 
ISC Idle
speed control or Idle compensation 
ISDN Integrated Services Digital
Network: digital telephone and data network with integrated services 

ISF Vehicle information system 
ISIS Intelligent safety system.
System with multiple airbags, pyrotechnically triggered headrests, seat-belt
tensioners and intelligent electronics (BMW) 
ISO International
Organisation for Standardisation 
ISO-EGO Isolated Exhaust Gas Oxygen
Sensor, isolierte unbeheizte Lambdasonde (mit Massekabel) 
ISO-HEGO
Isolated Heated Exhaust Gas Oxygen Sensor, isolierte beheizte Lambdasonde (mit
Massekabel) 
ISS Joint venture (Bosch, Michelin) for developing
integrated vehicle dynamics systems 
ISU Intelligent switching unit
(Siemens) 
ITGS


IVLAN Intelligent traffic guidance system (Mercedes)


In Vehicle Local Area Network
IWG Inductive travel sensor 
IWZ
Incremental angle/time sensor, rotation-angle sensor 
IZA Integrated
ignition system 
IZV Infrared central locking 
J Japan 

JA Jamaica 
JET Jet, Jetronic: injection system, usually proper
name 
JOBD Japanese OBD, OBD standard for Japan 
JTS Jet
thrust stoichiometric. Direct-injection petrol engine (Alfa) 
JW
Company car(s) 
K k: small K: channel K-line: bidirectional line
between control unit and tester 
KA Knee airbag 
KAM
Keep-alive memory 
KAT Catalytic converter 
KB Wire
harness 
KBA Federal Motor Vehicle Office (Germany) 
KBZ
Combination brake cylinder 
K-CAN Body CAN bus. Low-speed CAN bus for
comfort-system and body electronics. See also PT-CAN and SI-BUS. 
KD
Kickdown or Customer service 
KDS Kickdown switch 
KE
Continuous injection, usually proper name 
KE-MOTRONIC Continuous
electronic injection system, usually proper name 
KEN KEn: Jetronic,
continuous, with electronic extended-function unit, n=version, usually proper
name 
KF Fuel filter 
KFB Fuel filter, petrol or Comfort
zone 
KFMG Continuous delivery-volume meter 
KFZ Motor
vehicle 
KG kg: kilogram, physical unit, or Keyless Go (access to
vehicle and engine start without key) 
KG/H kg/h: kilograms per hour,
unit 
KGE Crankcase ventilation 
KIW Combined instruments with
service-interval indicator. See also SIA. 
K-JETRONIC Continuous
injection system, usually proper name 
KL KL or Kl: Terminal 

KLA Automatic climate control 
KM km: kilometer, physical unit KM:
small engine 
KMA Continuous volume analysis, product name
(Bosch) 
KMM Continuous volume meter, checks fuel delivery 

KMMG Continuous volume meter, closed 
KMV Refrigerant
compressor 
KOM Commercial bus and rental vehicles 
KOMP
Component 
KPA kPa: kilopascal, physical unit 
KPN Kpn:
Motronic (load detection occurs via intake manifold pressure, n=Motronic
version, usually proper name) 
KR Anti-knock control 
KRF
Kraftstoffrückführventil (Diesel) 
KRS Anti-knock control interface or
Fuel return valve 
K-RWG Short-circuit ring sensor 
KS Fuel
reservoir, or Knock sensor 
KSA Kingdom of Saudi Arabia 
KSB
Cold-start accelerator, with distributor injection pumps 
KSE
Child-seat detector 
KSH Cold-start aid 
KSP Fuel
reservoir 
KSS Cold-start control 
KSV Cold-start valve 

KSZ Fuel distributor or distribution 
KTF Fuel temperature sensor,
or Coolant temperature sensor 
KU Clutch 
KU/GN
Clutch/transmission neutral position 
KUKO Coupling head 
KVA
Fuel consumption gauge 
KVD Fuel evaporation 
KVR Fuel
distributor tube 
KVRS Evaporative emission-control regeneration
system, also referred to as tank ventilation system 
KVRV Fuel
evaporation regeneration valve, tank ventilation valve 
KVS Fuel
distributor piece 
KW kW: kilowatt, physical unit KW: crankshaft or
crankshaft angle or shortwave (radio) 
KWH kWh: kilowatt-hours,
physical unit 
KWP 2000 Keyword Protocol 2000, log for transmitting
diagnostic data 
KWS Comfort immobilizer 
KWT Kuwait 

KX Kx: Jetronic, continuous, with oxygen sensor control, usually proper
name 
KZS Capacitor intermediate storage 
L l: liter, physical
unit, or left L: left L-line: unidirectional line between control unit and
tester 
L/H l/h: Liters per hour, unit 
L/KM l/km: liters per
kilometer, unit 
LAM Idle emissions measurement 
LAV Luxury
activity vehicles (vehicle classification, such as Lexus RX 300) 
LC
Low compression, or Version with low compression ratio 
LCD Liquid
crystal display, usually proper name 
LDA Boost-pressure-dependent
full-load stop, with distributor injection pumps 
LDF Boost-pressure
sensor 
LDR Boost-pressure control, or Idle speed control 

LE2-JET Petrol injection, LE-Jetronic, 2nd generation, usually proper
name 
LED Light-emitting diode, usually proper name 
LEN LEn:
Jetronic, intermittent, covers European functionality, n=version, usually proper
name 
LER Idle limit-speed control 
LEV Low-emissions vehicle.
Designation for vehicles with low emissions level. See also NLEV, SULEV, TLEV,
ULEV, and ZEV. 
LFB Load-dependent start-of-delivery, with distributor
injection pumps 
LFR Idle compensation 
LFT Air temperature
sensor, or Long (term) fuel trim (to counteract aging symptoms). See also
LTFT. 
LHA Air-side automatic heater 
LHD Left-hand
drive 
LH-JETRONIC Same as L-Jetronic with hot-wire air-mass sensor,
usually proper name 
LHN LHn: Jetronic with hot-wire air-mass sensor,
intermittent, n=version, usually proper name 
LI (also li:) Left, or
Load index, number indicating tyre load capacity 
LIA Lift axle 

LIM Sedan 
L-JETRONIC Electronically controlled injection system
(with direct air-mass measurement), usually proper name 
LKE Load
piston unit 
LL Idle, engine operating state or Left-hand drive or LL
division, triangular division of brake circuits: 2 circuits in front, one in
rear 
LLDRAN Idle speed increase 
LLK Charge-air cooling 

LLR Idle control (diesel systems) 
LLRA LLRa: Idle control with
adaptive pilot control 
LLS Idle actuator, or Idle switch 

LL-STAB Idle stabilization 
LM Air-flow sensor (also LMM) 

LMF Light-alloy rims 
LMM Air-mass sensor, or Air-flow sensor 

LMS Air-mass sensor 
LN Ln: Jetronic with air-flow sensor,
intermittent, n=version, usually proper name 
LOS Emergency program
(EEC IV) 
LP Perforated plate 
LPG Liquefied petroleum gas,
fuel for vehicles with gas-powered engines 
LPS Circuit board
circuit 
LPT Printer port or interface on PC 
LR Oxygen sensor
control 
LRA LRa: oxygen sensor control with adaptive pilot
control 
LRD Load response drive, alternative multifunction
control 
LRR Smooth-running control, or Long-range radar (component of
ACC system with detection range up to 120 m) 
LRS Load response start,
alternative multifunction control 
LS Release switch or Oxygen
sensor 
LSCAN Low-speed controller area network. CAN bus with low
transmission rate (Opel). See also CAN, MSCAN, and HSCAN. 
LSD
Limited-slip differential 
LSF Oxygen sensor, planar (flat
sensor) 
LSH Oxygen sensor, heated 
LSM Oxygen sensor for lean
operation 
LSP Longitudinal lock shutoff 
LSU Wideband oxygen
sensor, planar type 
LSZ Light-switching centre 
LT Model
designation for VW Transporter, proper name 
LTCC Low temperature
cofired ceramic, multilayer ceramic technology 
LTF Air-temperature
sensor 
LTFT Long-term fuel trim (to counteract aging symptoms). See
also LFT. 
LTG Line 
LTR Liter, physical unit, often also ltr,
L 
LUN LUn: Jetronic, intermittent, with USA functionality, n=version,
usually proper name 
LWL Optical fiber 
LWR Headlight vertical
aim control 
LWS Steering wheel angle sensor. Component of ESP system,
determines steering-wheel rotation 
M M: Motronic, usually proper name,
or Mechanical or Mechanical fan or Centre m: Centre or Manual 
M/S2
m/s²: meters per second per second, physical unit for acceleration 

M3/H m³/h: cubic meters per hour, unit 
MA mA: milliampere,
physical unit MA: Mono-Motronic, petrol injection system, usually proper
name 
MAEL MaEl: earth (ground) electrode (spark plug) 
MAF
Mass airflow sensor 
MAL Malaysia 
MAP Manifold absolute
pressure or Intake manifold pressure sensor 
MAR Quantity compensation
control 
MAS Control unit for engine assembly 
MAT Manifold
absolute temperature 
MAX Maximum 
MBAR mbar: millibar,
physical unit 
MBS Engine-brake switch 
MBZ Diaphragm brake
cylinder 
MC Microcomputer or Medium compression 
MCC Micro
Compact Car. DaimlerChrysler subsidiary that manufactures the Smart
vehicle. 
MDA Engine speed increase 
MDF Mass of wheel-speed
sensor, usually with an indication of the particular sensor (left front, right
front, etc.) 
MDR Membrane pressure control 
ME Motronic with
electronic gas pedal, usually proper name, or Control unit for volume regulation
in diesel systems, usually proper name 
MEA Middle East 
MEAB
Mechanical shutoff device (diesel EDC). In newer systems, the shutoff is
electrical (see ELAB). 
MECH. Mechanical 
MED Motronic with
ETC and petrol direct injection 
MEG Motronic with ETC and transmission
control 
MEINS Meins: Injection volume (in mg/stroke or mg/s) 

MEN Monitor engine (output line for engine diagnostic data) 
MEP
Mean effective pressure 
MES Mechanically enabled start volume 

MEX Mexico 
MF Measurement window 
MFA Measurement window,
start or Multifunction display 
MFD Multifunction display 
MFE
Measurement window, end 
MFI Multipoint fuel injection
(electronic) 
MFI-C Continuous multipoint fuel injection
(electronic) 
MFI-I Intermittent multipoint fuel injection
(electronic) 
MFI-S Sequential multipoint fuel injection
(electronic) 
MFL Multifunction steering wheel 
MFR
Multifunction control 
MFS Multifunction sensor 
MFU
Multifunction clock 
MG Manual transmission 
MG/H mg/H:
milligrams per stroke, unit 
MG/ZYK mg/Zykl: milligrams per cycle,
unit 
MGND Engine ground (earth) 
MHDI Mechanical high-voltage
distribution ignition 
M-HEAT Mirror Heating, Spiegelheizung
(Opel) 
MI mi: Miles, physical unit MI: Malfunction indicator or Main
injection (see also HE) 
MIC Microplex (Marelli) 
MICROPLEX
Fully electronic ignition system with knock control 
MID Multifunction
information display 
MIEL MiEI: Middle electrode (spark plug) 

MIL Malfunction indicator lamp 
MIN
MIU Minimum
Main
Instrument Unit
MJ Mono-Jetronic, usually proper name or Model year 

M-JET Mono-Jetronic, usually proper name 
MK Motronic with
continuous fuel metering, usually proper name 
MKV Multiplicative map
adjustment, or Fuel ratio mixture 
ML Motronic with flap air-volume
sensor, usually proper name 
MLA Multiple link antitheft system
(system-wide theft protection) 
MLD Mechanical load-peak damping 

MLN MLn: Motronic based on air-flow sensor, n=version, usually proper name.
See also LM. 
MM mm: millimeter, physical unit 
MM3/H mm³/H:
cubic millimeters per stroke, unit 
MMI Engine torque, actual value or
Man-machine interface (Porsche designation) 
MMM Multipath map matching
(navigation system) 
MMS Engine torque, nominal value 
MMV
Quantity solenoid valve 
MN Mn: Motronic, universal load detection
(HLM, LM), n=version, usually proper name 
MNEFZ Modified new European
driving cycle (exhaust-gas test cycle). See also NEFZ. 
MODIC Mobile
diagnosis computer (BMW diagnostic tester) 
MOLIS Modular lights
system. LEDs in modular system for rear lights, for example (BMW) 
MOST
Media oriented system transport. Usually in conjunction with a bus system (MOST
bus), via which various control units in the vehicle communicate with each
other. 
MOT Engine tester, product name (Bosch) or Engine test 

MOT/DME Digital Motor Electronics (Motronic) 
MOZ Engine octane
number. Expresses the knock resistance of petrol fuel (US variant of ROZ). 

MP Motronic with intake manifold sensor, usually proper name 
MPA
MPa: megapascal, physical unit 
MPFI Multi-point fuel injection,
electronic, usually proper name 
MPH mph: Miles per hour, physical
unit 
MPI Multi-point injection, fully electronic engine control,
usually proper name 
MPN MPn: Motronic in which load detection is via
intake manifold pressure, n=version, usually proper name 
MPV
Multi-purpose vehicles (Mazda). Comprises the group of vans and small panel
trucks. 
MR Engine relay or Engine control for ASR 
MR-DF
Speed sensor with magnetoresistive measurement 
MRS Multi-restraint
system. Temic or BMW system consisting of belt tensioner, belt force limiting,
airbags, and safety battery terminal (see SBK). 
MS ms: millisecond,
physical unit MS: Engine control or Diesel systems with electronic volume- and
start-of-injection control 
MSA Designation for diesel injection
systems having an electronic volume control, start-of-injection control, and
exhaust-gas recirculation. Systems without exhaust-gas recirculation are
designated simply as MS. 
MSCAN Medium-speed controller area network.
CAN bus with medium transmission rate (Opel). See also CAN, LSCAN, and
HSCAN. 
MSG Engine control unit 
MSR Engine drag torque
control, usually proper name 
MST Measurement and control unit 

MSTS Microprocessor spark timing system, electronic ignition with map
control (ELZ), or Multi spark timing system, function as for EST. MSTS, however,
is not an integrated part but rather a separate ignition control unit 

MT Manual transmission or Mechanical transmission or Volume divider 

MTCO Tachograph 
MTM Engine measurement technology module 

MUD mUD: With vacuum 
MUX Multiplexer or multiplex signal 

MUXPORT Multiplexer-Port, Schnittstelle am PC, an die der Multiplexer
angeschlossen ist oder angeschlossen werden kann 
MV mV: millivolt,
physical unit MV: Solenoid valve 
MVEG Motor vehicle emission group,
exhaust-gas classification for passenger cars 
MVL Lift axle valve with
electronic air-cushioning system 
MVLDR Solenoid valve for boost
pressure control 
MVN Level valve with electronic air-cushioning
system 
MVS Solenoid valve control unit 
MW AM (radio), or
Measurement 
MY Model year 
MZ Magneto ignition 
MZV
Microprocessor-controlled ignition adjustment 
N n: RPM, or normal N:
Selector-lever position (Neutral) for automatic transmissions, or Norway 

NA Auxiliary drive or Netherlands Antilles 
NAS Auxiliary drive
switch 
NAV Navigation or Navigation system 
NB
Commercial-vehicle brake 
NBE Proximity detector 
NBF Needle
lift sensor (diesel) 
NBS Needle lift sensor (diesel) 
NCAP
New Car Assessment Program, better known as EURO-NCAP, association for
conducting more demanding crash tests (with participation of vehicle
manufacturers) 
NDS Neutral drive switch, activated when automatic
transmission selector lever is in neutral position 
NE NE:
After-injection Ne-Signal: Engine RPM signal, 24 AC signals sent to control unit
per distributor rotation 
NEDC New European driving cycle (procedure
for fuel consumption measurement). See also NEFZ 
NEFZ New European
driving cycle (procedure for fuel consumption measurement). See also NEDC 

NF Low frequency, or audio frequency 
NFZ Commercial vehicle
(lorry, truck) 
NHG Needle-displacement sensor (diesel systems) 

NHU Navigation head unit. Opel navigation control unit. 
NIC
Nicaragua 
NKW Lorry (truck) 
NKW-ABS Anti-blocking system for
lorries (trucks) with air brakes 
NL Netherlands 
NLEV
National low-emission vehicles. US approval level for vehicles that must fulfil
the current requirements. See also LEV, SULEV, TLEV, ULEV, and ZEV. 

NLK Follow-on piston 
NLS Needle lift sensor (diesel) 
NM
Nm: Newton-meter, physical unit 
NM/S Nm/s: newton-meters per second,
unit 
NMOT Nmot: Engine RPM 
NOE Nitrogen oxide emission 

NOX NOx: Nitrogen oxides 
NPB Delivery volume normal test stand
(special tester for injection pumps) 
NR Number, or Level control, or
Natural rubber (often processed for use in truck tyres). 
NRZ NRZ
format: Non-return-to-zero, transmission or pulse form for square-wave pulses
and signals 
NS Fog light(s) 
NSW Fog lights 
NTC
Negative temperature coefficient, thermal resistor with negative temperature
coefficient, so-called hot conductor 
NTC II Idle speed increase 

NTC1 Intake air temperature (in °C) 
NTC2 Engine water temperature
(in °C) 
NVF Navigation and traffic control 
NW Camshaft 

NWS Camshaft timing 
NZ New Zealand 
O2 Oxygen 

OAI Octane adjust input 
OBD On-board diagnostics or off-board
diagnostics, vehicle-internal diagnosis with internal or external test unit,
usually proper name 
OBF Upper control panel. Above or on the
dashboard, some vehicles have switches or buttons, such as for the rear-window
defogger. These elements together comprise a control panel, which is referred to
as the upper control panel to distinguish it from another control panel near the
gearshift lever or below the radio. 
OBM On-board measurement 

OC Oxidation catalytic converter 
ODFT Sensor for oil pressure and
temperature 
ODS Automatic overdrive control 
OEDS Oil
pressure switch 
OEF Location of missing vehicles (via GPS) 

OEM Original equipment manufacturer 
OES Original equipment
service. Service or spare parts via the vehicle manufacturer. 
OFFSET-V
Voltage offset 
OG Upper limit or Upper tolerance limit 
OHC
Overhead camshaft. Camshaft situated above the cylinder head. Often used in
engine designations. 
OHV Overhead valves (the camshaft is therefore
underneath) 
OMM Surface micromechanics 
OOP Out-of-position
detection 
OP Oil pump 
OPC Opel Performance Centre. Centre
for automotive sports (Opel). 
OR Logical OR operation 
OSRVM
Outside rear-view mirror (Opel) 
OT Top dead centre 
OTA
Oxygen/titanium emissions sensor. Titanium oxide sensor. See also OZA. 

OTF Oil temperature sensor 
OUD OUD: Without vacuum 
OUT
Designation on diesel pump for excess-flow restriction screw 
OZ Octane
rating. See also ROZ. 
OZA Oxygen/zirconium emissions sensor. Zirconium
oxide sensor. See also OTA. 
P Pressure, or Power train (used with OBD
error codes, for example), or Portugal 
PA Pa: pascal, physical unit of
pressure. See also HPA, KPA, and MPA. PA: Parking assistant 
PAG
Polyethylene glycol oil, low-temperature oil 
PAM Parking assistant
module (Opel) 
PANS Pans: Intake air pressure (in hPa) 
PAS
Peripheral airbag sensor (side airbag) 
PASE Passive start and entry.
Keyless access to car and engine start (Siemens system). Also called Keyless Go
(Mercedes, for example) 
PATA Passive button. Button in vehicle with
which a function can be set to the passive (off) state 
PATS Passive
antitheft system 
PB Pb: chemical symbol for lead (Latin:
plumbum) 
PBM Pulse width modulated, signal processing method (prior to
sending), usually proper name 
PBSL Park brake shift lock. Selector
lever lock for automatic transmission (Opel) 
PC Power control or
Personal computer 
PCM Power train control module or Porsche
Communication Management, central multimedia control unit for various
functions 
PCU Pump control unit (diesel systems), or Power control
unit, hybrid-drive control (Honda) 
PCV Positive crankcase ventilation,
closed crankshaft ventilation 
PD Pump-nozzle 
PDAS Dynamic
4-wheel control, usually proper name 
PDC Park distance control.
Parking aid, often proper name, or Pre-drive check (testing of EHB
systems) 
PDE Pump-nozzle unit (new designation is UIS) 
PDM
Passenger door module (Opel) 
PDOE Nozzle opening pressure 

PEHKS Pedestrian protection hood kinematics system. Ford mechanical system
that raises the hood (bonnet) in the case of an impact (such as hitting a
pedestrian). See also POBSY. 
PES Polyellipsoid system (headlight
technique) 
PES-SW Polyellipsoid headlight(s) 
PFA Particle
filter system 
PFI Port fuel injection, inlet-channel injection 

P-FP p-FP: Delivery pump pressure. 
PG Phase sensor 
PH
Pressure high, high pressure 
PHI phi: Greek letter used to designate
angles. 
PHS Park heater system 
PI Pilot injection. See also
POI, MI, and HE. 
PID Parameter identifier, part of CARB, code for
current values or similar parameters, usually proper name 
P-IN p-in:
Delivery pressure 
PIP Profile ignition pickup, ignition output circuit
(Ford) or Signal of Hall sensor for crankshaft RPM and position 
PJ
Pilot-Jection 
PKW Passenger car 
PL Country code for Poland,
or Pressure low, low pressure 
PLA Pneumatic idle increase or Pneumatic
idle stop 
PLD Pump-line-nozzle, diesel injection technique (new
designation is UPS) 
PLR Pneumatic idle speed control 
PLU
Pierburg measurement cell, or Pierburg Aviation 
PM Pump motor 

PML Parametric steering, assisted vehicle steering. The related data
(parameters) are stored in the control unit. 
PMR Private mobile
radio 
PMS Engine control with load detection via intake-manifold
pressure (Mercedes) or Inlet-channel injection 
PNAB Pneumatic
adjustment device 
PNABU Pneumatic adjustment device, vacuum-operated
(Bosch KH) 
PNABUE Pneumatic adjustment device, pressure-operated
(Bosch KH) 
PNG Papua New Guinea 
POBSY Pedestrian protection
optimised bumper system. Ford bumper system made from energy-absorbing foam
plastics to protect pedestrians. 
POI Post-injection. See also PI, MI,
and HE. 
POTI Potentiometer, variable resistance 
PPG PPG
module: Periphery program module; module containing control unit diagnostic
programs or other CompacSoft programs, proper name 
PPM ppm:
parts-per-million, unit 
PPS Pedal position system, or Pedal position
sensor 
PRC People's Republic of China 
PRG Program 

PROG Programming input 
PROM Programmable read-only memory, usually
proper name 
PRS Programmed restraint system. Reduces the seat-belt
tension and thus upper-body injuries (Renault) 
PS Test step or Pump
control or Horsepower, unit of work performed by motor vehicles 
PSA
PEUGEOT SOCIETE AUTOMOBILE, proper name 
PSD Pump control with
diagnosis or Porsche limited-slip differential, usually proper name 

PSE Pneumatic system electronics, electronically controlled pneumatic
system 
PSG Pump control unit 
PSI psi: Pounds per square
inch, physical unit 
PSM Porsche Stability Module. Porsche-specific
designation for ESP. 
PSP Power steering pressure 
PSPS Power
steering pressure switch 
PSV Partial intake-manifold pre-heating 

PT Power train 
PTC Positive temperature coefficient, thermal
resistor with positive temperature coefficient, so-called cold conductor, or PTC
heating element in intake manifold for delivering heat for evaporation 

PT-CAN Power train CAN bus. High-speed CAN bus for drive-train electronics.
See also K-CAN, SI-BUS. 
PTS Park-Tronic System. Parking aid. See also
PDC. 
PV Testing instruction 
PVS Vacuum switch 
PWG
Pedal position sensor, usually proper name 
PWL Power window
lifter 
PWM Pulse-width modulation, special signalling form used to
determine pulse-duty factors on components (for example, triggering of tank
ventilation valve is usually based on such a factor) 
PWR Pulse
rectifier 
PY Paraguay 
Q Quantity, usually of fuel 

Q1 Fuel quantity for cylinder 1. Similarly Q2, Q3, etc. 
Q-AVG
Quantity average. Mean of (fuel) quantity of all cylinders 
QB Quality
assessment 
QGS Quick glow system. Rapid pre-heating system for diesel
engines. 
QHS Quick heat system. Rapid diesel pre-heating system. 

QM Quality management 
Q-OVER Q-over: Overflow quantity 

QS Quality assurance 
QSF Average function 
QSL Quasi
select low 
QUADR Quadrifoglio, Alfa Romeo model designation 

RA Rear axle, or Argentina 
RAIL Common Rail, high-pressure
distribution line with Common Rail diesel systems 
RAM Random access
memory, read/write memory of a processor 
RAS Rear-axle steering.
Actively steered rear axle used in buses, for example. 
RB Robert
Bosch 
RC Remote control, or China (Taiwan) 
RCA Republic of
Central Africa 
RCH Chile 
RDK Tire pressure check system,
usually proper name 
RDS Rail pressure sensor or Radio data
system 
RDU Tyre pressure monitoring 
RDV Reverse-flow
throttle valve 
RDW Rest of the world (group in exhaust-gas
classification) 
RE Right (often "re") or Inline injection pump 

REA Resonance detection 
REC Rear electrical centre (Opel) 

REL Relay 
RF Radio frequency, radio signal 
RFP Return
pump 
RFS Backup light(s) 
RFT Run-flat tyre. Special tyre
that can also be used in an emergency. 
RG Route guidance (Travel
Pilot) 
RGS Route guidance standalone (Travel Pilot as standalone
system) 
RHD Right-hand drive 
RHO rho: Greek letter,
represents density (kg/m³) 
RHV Static high-voltage distribution 

RI Indonesia 
RIV Control pulse method (diesel) 
RKS Tire
check system 
RL
RLDM Right-hand drive
Rear Left Door Module

RLFS Fuel supply system without reverse flow 
RLV Reverse-flow
valve 
RM Reference mark 
RME Rapeseed methyl ester,
alternative fuel 
RO Romania 
ROK Republic of Korea 

ROM Read-only memory. Program memory of processor, or other memory, that can
only be read. 
RON Research octane number, see also ROZ 
ROPS
Rollover protection system. Automatically extendable rollbar (Volvo) 

ROV Rotating high-voltage distribution 
ROZ Research octane
number 
RP In-line pump, or Philippines 
RPA Flat tyre
indicator 
RPM
RRDM Revolutions per minute
Rear Right Door
Module
RS Restraint system or Rotational speed sensor 
RSC Run-flat
system component. Tyres with emergency-running properties. See also RFT. 

RSD Backflow throttle 
RSV Check valve, prevents undesired
reverse-flow of liquids or gases 
RTI Radio Traffic Information,
Verkehrfunk 
RTM Smoke opacity measurement module, product name for
exhaust-gas tester (Bosch) 
RTR Reverse-flow temperature control 

RU Soot concentration in exhaust 
RUE Soot emission 
RUEF
Retrofit vehicle 
RUM Soot amount 
RUV Static high-voltage
distribution, usually proper name 
RW Control travel 
RWAWS
Control-travel evaluation circuit 
RWD Rear wheel drive 
RWG
Control-travel sensor 
RX Receive line (contrast with TX line). 

RZ Wheel brake cylinder 
S S: Sensor, or super (premium) grade
fuel, or sport program (automatic transmission), or Sweden s: seconds 

SAC Self-adjusting clutch. Transmits only the current engine torque 

SACV Secondary air control valve 
SAE Society of Automotive
Engineers, US organization that prescribes standards, recommendations, or
guidelines for technically implementing legal requirements (such as for engine
oil, error codes, data transmission, etc.) 
SAM Safety (or signal
detection) and triggering module. Designation for Mercedes control unit. 

SAS Side-impact protection 
SAT Siemens adaptive transmission
control 
SAV Overrun cutoff valve, or Sport activity vehicles (for
example BMW X5) 
SB Star-of-injection, indicates when fuel injection
actually starts (the start-of-delivery on the other hand is the time at which
the fuel pump begins to deliver), or Control unit for start-of-injection control
(diesel) 
SBB Disc-brake lining 
SBC Sensotronic Brake
Control, part of EHB (electrohydraulic brake) system 
SBE Seat-occupied
detection 
SBK Safety battery terminal. Part of airbag system. In the
case of an accident, the battery is rapidly disconnected from the starter cable
in order to prevent short circuits and reduce the risk of fire. 
SBR
Start-of-injection control 
SBS Speech-based operation system (Porsche
designation) 
SCAN TOOL Tester for reading OBD error codes and other
OBD data 
SCC Safety car concept. Volvo concept for vehicle in which
many safety features have been integrated 
SCHALT Switch 
SCHR
Steps, such as with a stepping motor 
SCI
SCL Smart-charged
injection. Petrol direct injection (Ford)
Steering Column Lock
SCP
Serial communication protocol, proper name 
SCS Stability control
system. Simplified form of ESP (Mitsubishi). Prevents vehicle tilting or
skidding. 
SCU Sensor and control unit. Control unit with integrated
radar sensor, main component of ACC system. 
SD Intake manifold
pressure, or Sunroof, or Injection duration, or Control unit diagnosis 

SDI Intake diesel injection 
SDL Service diagnosis line, product
designation for test line (Bosch) 
SDM
SDM Sunroof motor or Control
unit diagnosis module
Sensing and Diagnostic Module (airbag)
SDS
Intake-manifold pressure sensor 
SDW Signal from anti-theft warning
system 
SEC Seconds, physical unit 
SEFI Sequential fuel
injection, usually proper name 
SELECT HIGH Select-high control for
commercial-vehicle ABS systems. The pressure level is geared to the wheel
running with the higher coefficient of friction. 
SELECT LOW Select-low
control with commercial-vehicle ABS systems. Pressure level depends on wheel
running with the lower coefficient of friction 
SET CONTROLLER Program
command related to controller 
SFI Sequential multipoint fuel
injection 
SFT Short (term) fuel trim (lambda-parameter correction).
See also STFT. 
SG Control unit 
SGP Singapore 
SHD
Sliding or lifting sunroof 
SHR Select-high control for
commercial-vehicle ABS systems. The pressure level is geared to the wheel
running with the higher coefficient of friction. 
SHZ Heated seat 

SI Speed index (code letter for speed), or Silicon 
SIA Service
interval indicator. Shows the driver that oil change or annual inspection is
required, for example. See also WIV. 
SI-BUS
SID
SIDC Safety and
information bus system. See also K-CAN and PT-CAN.
System Information
Display
Sid Controller
SIH Sitzheizung 
SIL Seat electrical
system, left 
SILA Signal lamp 
SIM Safety information module.
Component of ISIS system (BMW) 
SIPS Side-impact protection system
(Volvo) 
SIR Seat electrical system, right. 
SIS Service
Information System, proper name or Series repair 
SKF Spike
characteristic. Relates to Porsche transmission controls. 
SKO
Compressor signal 
SKT Scale units 
SL Select low 

SLA
 Safety lamp
 
SLE
SLM Secondary-air injection

Shift lever Module
SLO Slovenia 
SLP Secondary-air pump 

SLR Select-low control for commercial-vehicle ABS systems. The pressure
level is geared to the wheel running with the lower coefficient of
friction. 
SLS Secondary-air system 
SM Seat memory, or
Stepping motor 
SME Stepping-motor electronics 
SNA Automatic
momentum utilisation 
SNR Part number or Record number 
SO
Safety switch, normally closed (actuator) 
SO2 Sulphur dioxide. Pungent
gas causing respiratory diseases. It is thus an aim to reduce the sulphur
content in exhaust gases. 
SOHC Single overhead camshaft 
SOP
Start of production 
SP Safety testing, usually in conjunction with
testing of brake system 
SPA
SPA Mirror drive
Sonic Park Assist

SPI Single point injection, usually proper name 
SPL Noise level,
or Sound-pressure level 
SPM Mirror memory, usually proper name 

SPOR Sporadic 
SPOUT Ignition signal (EEC IV) 
SPS Solar
position sensor 
SPV Injection adjustment (see also SV) 
SR
Side-based control 
SRA Headlight wiper system 
SRC Source (of
data or audio signals, for example) 
SRE Intake-manifold
injection 
SRM
SRM Headlight wiper motor
Sun Roof Module
SRS
Safety restraint system (generally includes airbag and seatbelt tensioner,
normally controlled by a common control unit) 
SS Safety switch,
normally open (sensor 9) 
SSA Automatic start/stop 
SSD Steel
sliding sunroof 
SSG Seat control unit (Mercedes) 
SSHD Steel
sliding/lifting sunroof 
SSS Stop/start system 
SST Special
tool or self-supporting tyre, tyre which supports itself and features limp-home
properties 
SSU Triggering device for side airbag 
ST System
tester 
STAE Start external, external start switch 
STAT
Static 
STC Stability and traction control 
STFT Short-term
fuel trim (for lambda-parameter correction). See also SFT. 
STH
Stationary-vehicle heater 
STI Self-test input signal 
STM
Servomotor 
STO Self-test output signal 
STOE Stop external,
external stop switch 
SU Soviet Union 
SULEV Super ultra-low
emissions vehicle (group in classifying exhaust-emissions levels). See also LEV,
NLEV, ULEV, TLEV, and ZEV. 
SUS Slip threshold switchover 
SUV
Sport utility vehicles. Vehicle group comprising off-road-capable,
leisure-activity sport vehicles and commercial vehicles with all-wheel drive
(fun vehicles). Better suited for on-road than off-road. Examples: Mazda
Tribute, Mercedes ML 320. 
SV Injection adjustment (see also SPV) or
Servo valve or Start valve 
SVC Saab variable compression. The cylinder
head is tilted in order to modify the compression ratio, or Speed volume
control. Speed-dependent volume control for car radios. 
SVG Seat
adjustment transmission 
SVM Seat adjustment motor 
SW
Headlight(s) or Software 
SWA
SWC Headlight washer
Steering
Wheel Control
SWD Vibration damper 
SWT Side wall torsion sensor.
Detects longitudinal and transverse forces directly at the wheel during
acceleration, braking, and in curves. Currently employed for quick-reaction ABS
and ESP systems, in the future possibly for counteracting wind gusts. 

SZ Opacity number, or Coil ignition, possibly with interrupt contacts or
Switching-time program (determines switching time) 
T t: (such as
t-adj., time of adjustment) T: temperature (such as T-comp, compression
temperature) 
T.C.S. Ignition timing control system 
T.O.C.S.
Throttle valve control system 
TA Traffic announcement, or Thorax
airbag (BMW) 
TAB Test Airbag. Excitation lead for airbag system
(Mazda) 
T-ABGLEICH t-adjust: time of adjustment 
TAC Test Air
Conditioning. Excitation lead for air conditioner (Mazda) 
TANS Tans:
Intake air temperature (in °C) 
TAS Temperature dependent control, with
distributor injection pumps, or Temperature dependent start-volume, with
distributor injection pumps 
TAT Test Automatic Transmission.
Excitation lead for transmission control (Mazda) 
TAU Automatic
temperature system 
TBB Drum-brake shoes 
TBI Throttle body
injection, central injection 
TBS Test Brake System. Excitation lead
for ABS system (Mazda) 
TC Traction control, auxiliary function with
ABS 
TCE Trailer central electronic, central electronics system for
trailer 
TCM Transmission control module (Opel automatic-transmission
control unit) 
TCO Tachograph (Mercedes) 
T-COMP T-comp:
Compression temperature 
TCS Traffic centre service 
TCSA
Temperature controlled spark advance 
TCU Transmission control
unit 
TD TD: Time division, engine load signal tD: Transistor speed
signal, square-wave signal supplying RPM for other systems such as transmission
control 
TDC Top dead centre, see also OT 
TDI Turbo diesel
injection 
TDS Tank pressure sensor 
TEC Total electronic
control 
TEE Tank installation unit 
T-EIN t-ein: Build-up
time 
TELE-AID Telematic alarm identification on demand, accident
notification 
TEMP


TMS Temperature


Telematics
TEMP. SCH. Temperature switch 
TEMPF Temperature
sensor 
TEN Test Engine. Excitation lead for control unit (Mazda),
usually proper name 
TES Thermo-electric switch or tank ventilation
system (also referred to as evaporative emission-control regeneration
system) 
TEV Tank ventilation valve or Thermostatic expansion valve
(heating/air conditioning) 
TF Temperature sensor 
TFA Test of
radiator fan 
TFI Electronic ignition switch (EEC) 
THA
Thailand 
THS Toyota hybrid system. Hybrid of combustion and electrical
drive, with electronic control. 
T-HYBRID Hybrid temperature 

THZ Tandem master cylinder. Master brake cylinder for hydraulic
brakes. 
TI ti: Injection signal (t=time, i=ignition) 
TID
Test identification data or Triple Info Display, driver information system in
which certain data and information is displayed 
TIM Time impulse 

T-IN T-in: Inflow temperature (actual) T-in (nom.): Nominal inflow
temperature 
TIPTRONIC Porsche or VW electronic transmission control.
The control can be operated via a small device on the steering wheel. 

TKRAFT Fuel temperature (in °C) 
TKU Technical customer
documentation 
TL tl: Engine load signal recorded over time TL: Partial
throttle, engine operating state 
TLA Temperature dependent idle
increase, with distributor injection pumps 
T-LASTPUNKT Time of load
point 
TLEV Transient low-emissions vehicle (group in exhaust-emissions
classification). Comprises vehicles with low emissions levels. See also LEV,
NLEV, SULEV, ULEV, and ZEV. 
TLK Temperature dependent idle
correction 
TMB Door module, passenger side 
TMC Traffic
message channel 
T-MESS Time or duration of measurement 
TMF
Door module, driver side 
TMOT Engine temperature (in °C), usually
determined from coolant 
TMS Telematic system 
TN tn: Signal
from ignition with inductive peaks suppressed. Used for RPM detection for
control unit and speedometer 
TNA Signal output for engine speed. 

T-OFFSET Time offset 
T-OVER T-over: Overflow temperature 

TP Throttle valve potentiometer (actuator) 
TPM
TPM Tempomat
(cruise control)
Tyre Pressure Monitoring
TPMS Tyre pressure monitoring
system, with pressure and temperature sensors at wheel (Opel/Teves) 

TPS Throttle position sensor 
TQ Time quantity (usually TQ signal).
Fuel consumption signal. 
TR TR: RPM information, or contact roller, or
Turkey tr: Calculated RPM signal 
TRACS Traction control system
(Volvo) 
TRUST Trundle stability 
TS Temperature switch or
Twin spark, double-spark ignition (Alfa Romeo) 
TSG Tank level sensor
or Door control unit 
TSH Door lock heater 
TSP Trailer
stability program, ESP type system for trailers, designed to prevent trailer
skid (Opel) 
TSS Thermal protection switch 
TSU Speedometer
signal transformer 
TSZ Transistor coil ignition with discrete
components 
TSZ-H Transistor coil ignition with Hall sensor 

TSZ-I Transistor coil ignition with inductive sensor 
TSZ-IZA
Transistor ignition with ignition coil in distributor 
TT TT division.
Black-and-white division of brake circuits: one circuit in front, one in
rear. 
T-TOTAL t-total: Total measurement time 
TUEV German
vehicle-inspection authority 
TV TV: Timing valve tv: Offset time of
oxygen sensor control 
TVA Temperature dependent full-load stop 

T-VIS Toyota variable intake system (cut-in at 4500 rpm in 16-valve
engines) 
TVS Temperature dependent vacuum switch or Thermal vacuum
switch 
TVSV Temperature dependent vacuum switching valve 
TWA
Twin-wheel axle. Axle with twin tires on each side. 
T-WAIT t-wait:
Wait time 
T-WARTE Wait time 
TWC Three-way catalytic
converter 
TX TX line: Transmission line, in contrast to RX line 

TZ Transistor coil ignition with hybrid component 
TZ-H Transistor
ignition with Hall sensor 
TZ-I Transistor ignition with inductive
sensor 
TZS Thermal time switch 
U Below, underneath or
Voltage 
UAE
UAM United Arab Emirates
Ultrasonic Alarm Module

UB Battery voltage, supply voltage at terminal 30 
U-BATT Battery
voltage 
UBF Lower control panel. Near the gearshift lever or below the
radio, some vehicles have switches or buttons, such as for the rear-window
defogger. These elements together comprise a control panel, which is referred to
as the lower control panel to distinguish it from another control panel on or
above the dashboard. 
UBL Brake-light voltage 
UCL
Understeering control logic. ESP system used in Renault Megane. 
UDB
Vacuum limiter 
UD-F Vacuum adjustment EARLY 
UD-MODUL Vacuum
module. Valve for switching and measuring intake manifold pressure 
UDS
Accident data memory (VDO), similar to black box in aircraft 
UD-S
Vacuum adjustment LATE 
UEC Underhood Electrical Center, Opel
designation for engine-compartment electronics module 
UEDS
Excessive-speed switch 
UEGO Universal exhaust gas oxygen sensor,
non-heated Lambda sensor 
UERB Rollbar 
UEV Excessive-flow
valve 
UG Lower limit Lower tolerance limit 
UIS Unit
injection system, new designation for PDE systems (diesel injection systems with
pump-nozzle unit) 
U-KAT Unregulated catalytic converter (without
oxygen sensor control) 
ULEV Ultra-low emissions vehicle (group in
exhaust-gas classification). See also LEV, NLEV, SULEV, TLEV, and ZEV. 

ULW Ultra lightweight 
UM Reversing valve (for ASR operation) 

UMTS Universal Mobile Telecommunications System. Standard for the 3rd
generation of mobile radio communications. Is to replace the analogue radio
system over the long term. 
UNI1 UNI2,Additional lines on universal
adapter cable, used to read out flash codes or for special purposes 
UP
Unsaturated polyester. Thermosetting plastic used in body construction or to
manufacture pressure-resistant containers. 
UPA Ultrasonic parking
assistant 
UPS Unit Pump System, new designation for PLD systems 

URS Rollover sensor, usually proper name 
US Designation denoting
basis on U.S. emission standards 
USA United States of America 

USB Universal serial bus. The USB interface permits simple connection of
various peripherals to a PC. 
USG Non-interrupting manual transmission.
Two clutches (drive-off and load-shift) enable electronically controlled driving
without shifting interruptions. 
USV Change-over valve 
UT
Bottom dead centre 
UUV Urban Utility Vehicle, Nutzfahrzeug für den
Einsatz in der Stadt 
UV Ultraviolet. Used mostly in conjunction with
light or radiation. 
UVR Voltage at valve relay 
UVS Rollbar
and variable sunroof control (Mercedes) 
UW Voltage converter 

UZ Voltage after ignition, terminal 15 
V V: Volt, physical unit,
or carburetor engine, or valve, or viscose, or fan, or front v: Front, or
velocity 
V/MS V/ms: volts per millisecond, unit for voltage per
time. 
VA Vorderachse 
VAC Variant coding 
VAF
Air-flow sensor 
VAG Volkswagen AG, vehicle maker, proper name 

VAKU-SCH. Vacuum switch 
VAN Vehicle Area Network. The VAN bus is a
bus system that interconnects various components in the vehicle. This can be a
CAN bus, but it can also be another type of bus. 
VANOS Variable
camshaft timing 
VARILIS Variable lighting system (Hella) 
VAT
Intake-air temperature sensor 
VC Variant coding 
VCV Vacuum
control valve 
VD Choke valve 
VDC Vehicle distance control or
Vehicle dynamics control 
VDV Vacuum delay valve 
VE
Distributor injection pump (series designation). See also VP 
VERD.
Verdeck (Cabrio) 
VES Fully electronic radio ignition key 
VEZ
Fully electronic ignition system 
VFD Vacuum fluorescence display 

VFR Variable focus reflector (headlight) 
VGWX Preset value if
sensor fails 
VIM Vehicle immobilizer 
VIN Vehicle
identification number, code stored in control unit 
VIS Variable Intake
System (Rover) 
VK Valve body 
VKP Programmable variant
coding 
VKS Variant coding with plug 
VL Left front, or Full
load, engine operating state 
VLP Preliminary charge pump 
VM
Adjustment motor or Combustion engine 
VOCS Voice control system 

VP Distributor pump (usually factory-internal designation). See also
VE 
VPC Volvo Personal Communicator. SCC element with fingerprint
sensor that detects the identity of the driver and makes driver-specific
adjustments. 
VR Right front or Distributor pump with radial
piston 
VRD Vario nozzle, nozzle with variable radius 
VRM
Valve feedback 
VRS Relay supply voltage 
VSA Vehicle
stability assist. System similar to ESP. 
VSC Voltage supply control.
Battery management system (Mercedes) 
VSG Composite safety glass 

VSO Vehicle speed out 
VSS Volts peak-to-peak, unit for special
voltage values, measures difference between maximum and minimum voltage levels
or Vehicle speed sensor, or Vehicle security systems 
VSV Vacuum
switching valve 
VT Vacuum transducer 
VTG Variable turbine
geometry. The turbine has movable guide blades, which can be varied depending on
the operating state of the vehicle. A turbocharger with variable turbine
geometry offers the advantage that it is more responsive than a conventional
turbocharger with fixed turbine geometry. 
VTV Vacuum transmitting
valve 
VVA Variable valve actuation. Variable valve control between
cams and valves. Operates electrohydraulically. Duration and width of opening
can be varied (Fiat, Lancia) 
VVC Variable valve control 
VVL
Variable valve lift 
VVW Variable valve displacement 
VW
Compensating resistor or Volkswagen, vehicle maker, proper name 
VZ
Electronic ignition timing with static distribution 
VZ-K Electronic
ignition timing with static distribution and knock control 
W/M2 W/m².
Watts per square meter. Physical unit for solar radiation intensity 

WAA Wiper blade 
WALA Safety lamp 
WAN Nigeria 

WDS World diagnostic system (Ford tester) 
WE Water injection 

WEBER Weber petrol injection 
WEO Western Europe except
Germany 
WFS Immobilizer 
WHA Water-side automatic
heater 
WIG Wiper pulse transmitter 
WIV Service interval
extension. Under certain conditions (use of special oils, etc.), service can be
performed at greater intervals. Also referred to as Longlife Service (VW,
Audi). 
WK Converter clutch 
WL Warning lamp 
WLR
Warmup control 
WR Warmup control or Warning lamp relay 
WS
Wiper or Travel sensor 
WSA Wiper system 
WSG Separate control
unit 
WSH Wiper lever 
WSK Converter clutch used in
semiautomatic transmission 
WSKS Converter clutch switch 
WSM
Wiper motor 
WSS Window screen system. A type of night-vision unit
(DaimlerChrysler). Supports driver in night driving by making an infrared image
of what is visible through the windscreen and displaying it on a separate
screen. 
WSZ AC ignition 
WT Heat exchanger 
WTF
Water temperature sensor 
WUEK Eigentlich WÜK,
Wandlerüberbrückungskupplung, verhindert Schlupf im Drehmomentwandler 

X X division. Diagonal division of brake circuits: one circuit for
left-front and right-rear, and one circuit for right-front and left-rear. 

XE Extreme economy. Selection option for extremely economical driving with
automatic transmissions 
XS Extreme sport. Selection option for
extremely sporty driving with automatic transmissions 
YRS Yaw rate
sensor. Component of ESP system 
YV Venezuela 
Z.Z. Currently,
at the moment 
ZA Ignition suppression or South Africa 
ZAB
Central display and operating unit for information 
ZAS Cylinder
shutoff 
ZBR Central vehicle computer 
ZDA Intermediate RPM
stop 
ZDE Intermediate RPM adjuster 
ZDR Intermediate RPM
control 
ZDT Cyclical nozzle-exchange procedure 
ZE Central
injection or Central electronics 
ZEE Central injection unit,
Mono-Jetronic 
ZEV Zero-emissions vehicle. Vehicle producing no exhaust
gases. See also LEV, NLEV, SULEV, TLEV, and ULEV. 
ZGM Central gateway
module 
ZGW Central gateway. Computer that connects and controls data
exchange between two networks 
ZK Ignition circuit (airbag
system) 
ZKO Ignition capacitor 
ZLS Auxiliary air
slider 
ZLV Auxiliary air valve 
ZME Trim unit. Control unit
for the high-pressure pump (such as CP3) of a Common Rail system. Measures the
fuel quantity fed to the pump. 
ZMS Two-mass flywheel 
ZNPB
Central delivery volume normal test stand (special tester for injection
pumps) 
ZOS Zero offset disc brake (no residual drag moment) 

ZOT Cylinder top dead centre 
ZRE Zaire 
ZS Ignition
coil 
ZU Intermediate inspection 
ZUS.LUFTP. Auxiliary air
pump (secondary air injection) 
ZV Central locking or Ignition
distributor or Ignition timing adjustment 
ZVM Central locking
module 
ZVN Central valve for level adjustment 
ZW
Between 
ZWD Two-coil actuator (servomotor with two coils)  
ZWG Intermediate transmission 
ZWS Accessory for immobilizer  
ZWV Ignition timing adjustment 
ZYL Cylinder