StephanZ
Constant problems with the trunk lock on my BMW 3 Series - What could be the cause?
Locking/Unlocking issue
(Translated from German)
3 comment(s)
@CarlyMechanic
It sounds like you're dealing with a complex electrical issue. The OBD error code 009CB4 is related to the footwell module, which controls various electrical functions in your car, including the trunk lock. The recurring problems with different electrical components and the discrepancy in the mileage could indicate a problem with this module or the car's wiring.
I would suggest starting with a thorough check of the car's electrical system, including the footwell module and the wiring. If you're not comfortable doing this yourself, it would be best to take your car to a professional mechanic.
Please keep us updated on your progress. Do you have any other questions?
Another observation I remember was during the last drive before the last trunk lock failed (was installed afterwards) that the board voltage displayed via Carly was consistently >15V. After the trunk lock failed, I left the car outside for several hours (at about 0°C) to drive it into the garage later. It started up reluctantly, and a short time later no longer started in the garage. The board voltage was only 11.56V (displayed via Carly), while the battery voltage was still 13.3V. Could these observations also have something to do with the problem?
(Translated from German)
@StephanZ
Another observation I remember was during the last drive before the last trunk lock failed (was installed afterwards) that the board voltage displayed via Carly was consistently >15V. After the trunk lock failed, I left the car outside for several hours (at about 0°C) to drive it into the garage later. It started up reluctantly, and a short time later no longer started in the garage. The board voltage was only 11.56V (displayed via Carly), while the battery voltage was still 13.3V.
Could these observations also have something to do with the problem?
Yes, these observations could indeed be related to your problem. The voltage readings you're getting are abnormal. A healthy car battery should read around 12.6 volts when the car is off, and between 13.7 to 14.7 volts when the car is running. The high voltage (>15V) could indicate a problem with the alternator overcharging the battery, while the low voltage (11.56V) could suggest a weak battery or a problem with the charging system. Both of these issues could affect the electrical components in your car, including the trunk lock. I would recommend having your battery and alternator tested. If they're both in good condition, then the problem might be with the voltage regulator, which is often part of the alternator but in some cars is a separate component or part of the ECU. Please keep us updated on your progress. Do you have any other questions?
It sounds like you're dealing with a complex electrical issue. The OBD error code 009CB4 is related to the footwell module, which controls various electrical functions in your car, including the trunk lock. The recurring problems with different electrical components and the discrepancy in the mileage could indicate a problem with this module or the car's wiring. I would suggest starting with a thorough check of the car's electrical system, including the footwell module and the wiring. If you're not comfortable doing this yourself, it would be best to take your car to a professional mechanic. Please keep us updated on your progress. Do you have any other questions?