W251 2009 R350 CAN-bus communication gremlins
#1
02-25-2024, 06:02 AM
W251 2009 R350 CAN-bus communication gremlins
Good afternoon,
I have been experiencing serious electric issues since over a year but I did not have to use this car much so it wasn't my priority.
Now, I would like to enjoy it but it is giving me serious / random / intermittent electric issues.
After a lot of digging, I have come to the conclusion that I have either a faulty module that blocks the whole system, or a communication issue directly on the CAN bus.
I have changed ISM, main and auxiliary batteries.
I have checked all fuse and relays (removed, tested and placed back).
When the issue is not present, the diagnostic toold doesn't read any critical fault that would lead to the repeating problem. Car starts without issue and all organs seems to be working.
When it happens, the only way to get out off the limb mode is to disconnect the battery. If a gear is already engaged, it will still drive but not turning signal, no wipers..., rough gear changes and only forward (no change allowed).
The issue has been appearing more frequently lately.
Worth noting that I have check and have not found any trace of water under the driver and passenger foot, nor below the spare wheel (I live in KSA and rain is pretty rare here...)
I haven't found any signs of corrosion wether on the electronic boards nor in the coneectors in those area neither.
I want to attach below 2 OBD-II reports:
- 1st with the car working fine and showing no major DTC
- 2nd one, 5 minutes later, after having all the dash lights on and blinking, showing no more communication with the main engine and drivetrain modules...
Has any of you experienced such issue ?
Any ideas ?
Next step would be to measure hi-CAN bus abd low-CAN bus voltages to try to find a faulty moduel somewhere but I am not extremely confident with this procedure...
Thank you in advance
I have been experiencing serious electric issues since over a year but I did not have to use this car much so it wasn't my priority.
Now, I would like to enjoy it but it is giving me serious / random / intermittent electric issues.
After a lot of digging, I have come to the conclusion that I have either a faulty module that blocks the whole system, or a communication issue directly on the CAN bus.
I have changed ISM, main and auxiliary batteries.
I have checked all fuse and relays (removed, tested and placed back).
When the issue is not present, the diagnostic toold doesn't read any critical fault that would lead to the repeating problem. Car starts without issue and all organs seems to be working.
When it happens, the only way to get out off the limb mode is to disconnect the battery. If a gear is already engaged, it will still drive but not turning signal, no wipers..., rough gear changes and only forward (no change allowed).
The issue has been appearing more frequently lately.
Worth noting that I have check and have not found any trace of water under the driver and passenger foot, nor below the spare wheel (I live in KSA and rain is pretty rare here...)
I haven't found any signs of corrosion wether on the electronic boards nor in the coneectors in those area neither.
I want to attach below 2 OBD-II reports:
- 1st with the car working fine and showing no major DTC
- 2nd one, 5 minutes later, after having all the dash lights on and blinking, showing no more communication with the main engine and drivetrain modules...
Has any of you experienced such issue ?
Any ideas ?
Next step would be to measure hi-CAN bus abd low-CAN bus voltages to try to find a faulty moduel somewhere but I am not extremely confident with this procedure...
Thank you in advance
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