I have a 2011 Opel Astra J that shows two notices on start-up:
- broken right city light (message shown is in Dutch, my translation)
- service brake lights (message shown is in Dutch, my translation).
While the light seems to work fine.
Originally only the first notice was shown. The right tail light was emitting light, but I replaced it none the less. This did not resolve the issue, message was still shown.
When switching both rear bulb-mounting assemblies (left and right, plugs are compatible), the message remains that the right tail light bulb is defective.
If I unplug the left tail light assembly, a message is shown for both left and right tail lights.
Measuring the voltage over both left and tail light (at the level of the metal conducting strips in the tail light assemblies) gives the exact same value, 11.48V when battery voltage is approximately 12.5V.
Measuring the voltage from another ground to the negative bulb terminal yields 40mV.
There's one present DTC in the BCM, B3881-04 - Rear Left Tail Light Circuit Open. Status:Present
I suspect this saying "left" rather than "right" is an error in the ScanMyOpelCAN application.
Some other DTC's regaring rear wiper, windshield washer pump relay, front washer relay circuit and high speed comunication enable circuit are logged but not active.
If it were a grounding issue, would the voltage over the right bulb not be less than the voltage over the left bulb?