VW Polo Electrical faults
Customer reported fault: Vehicle will start up fine. Eventually, the power windows will stop operating, the horn will not work, central locking will become inoperative, engine warning light will illuminate.
Fully equipped with dealer tooling & technical information, we performed a diagnostics scan using vcds V2 to try & perform a test plan. Fault code 00532 Supply voltage B+ This was the fault that stood out. We are losing several circuits & we had a permanent issue with a power supply.
In using the vcds, we can be certain that the live data pids we view will be accurate & not substituted like other aftermarket scan tools can do.
Straight away we notice almost a 2v voltage difference between “reference” & “terminal 30”.
Fully equipped with dealer tooling & technical information, we performed a diagnostics scan using vcds V2 to try & perform a test plan. Fault code 00532 Supply voltage B+ This was the fault that stood out. We are losing several circuits & we had a permanent issue with a power supply.
In using the vcds, we can be certain that the live data pids we view will be accurate & not substituted like other aftermarket scan tools can do.
Straight away we notice almost a 2v voltage difference between “reference” & “terminal 30”.
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We decided to put the vehicle under load, looking for the voltage possibly dropping more once these circuits that are dropping out are adding a load.
Here is what we found next... The power supply voltage dropped to 2v.. At this point, we confirmed the loss of operation on these electrical circuits. Time just find out where the power supply comes from. |
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Using genuine technical data, we found the supply wire on the J519 unit suspect of power loss.
A main supply not only for the central electronics unit, but also the engine ecu. Which confirms the customer complaint for engine light also.
The test light showed a bright light initially, but with the multimeter attached we see the voltage drop to 8v, gradually getting worse.
A main supply not only for the central electronics unit, but also the engine ecu. Which confirms the customer complaint for engine light also.
The test light showed a bright light initially, but with the multimeter attached we see the voltage drop to 8v, gradually getting worse.
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The fuse & terminals of the fuse holder tested to be good. We notice in the wiring diagram earlier that this 5a fuse actually supplies power to 5 components. A shared & suspect issue for this was the B111 splice connector that is located somewhere in the dashboard harness.
Due to the sheer size of the job, we quickly provided a resistance free route for the power but “bypassing” the splice. We run a new wire from the fuse terminal to the J519 unit.
Here was the outcome...
Due to the sheer size of the job, we quickly provided a resistance free route for the power but “bypassing” the splice. We run a new wire from the fuse terminal to the J519 unit.
Here was the outcome...
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Our “reference” now matched our “terminal 30”. Under load the 2 data pids still matched & we could confirm a fix.
Genuine equipment is essential for diagnostics purposes on today’s modern vehicles. Along with speed & reliability of the vcds, it’s a must have! Auto scan to complete the job, and we are happy with the results. Thanks to Tom at East Manchester Auto electrical. |
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