ECU failure due - oil contamination?
Thread Starter
Junior Member
Joined: Sep 2017
Posts: 39
Likes: 2
2011 W204 C180 GGI (FL)
ECU failure due - oil contamination?
Hi folks, would like to get your opinion or suggestions regarding my E230 W211 (M272 E25 engine) AMG line. Current mileage is 70k kms.
Basicslly, I went to start the car up a few nights ago and everything was normal. Went back inside the house to grab a few stuff, and when I got into the car, the engine was dead. Tried to restart the car, and it failed to start, not even crank. Nothing happened when turning the key to the “start” position. Instrument cluster displayed “ESP inpoerative” and “Run flat indicator inoperative”. Next day, got the car towed to the dealership, thought it would just be a simple fix as car drove normally before the incident and no CEL.
To my shock, dealership quoted me a $5k repair bill including replacement of ECU and wiring harness due to the infamous camshaft magnet leak. I went to inspect the cam magnet connectors, fair enough there was a bit of oil, maybe damp, but not drenched. The ECU connectors looked dry. The STAR diagnosis report showed the ME 9.7 (ECM) module had no serial number, i.e. failure to communicate, and that other modules are showing errors like “No CAN message received from ECM”.
I’m not 100% sure if replacing the ECU is necessary as I see others have had their ECU drenched with oil and upon cleaning, car drives well with no issues. To you guys out there whom experienced this before, would cleaning the harness and connectors be sufficient? Perhaps it was just a fuse breakage caused by the electrical short? Any other suggestions are welcome. Not looking to drop $5k on the car currently.
Look forward to hearing your thoughts.
Mo420
Basicslly, I went to start the car up a few nights ago and everything was normal. Went back inside the house to grab a few stuff, and when I got into the car, the engine was dead. Tried to restart the car, and it failed to start, not even crank. Nothing happened when turning the key to the “start” position. Instrument cluster displayed “ESP inpoerative” and “Run flat indicator inoperative”. Next day, got the car towed to the dealership, thought it would just be a simple fix as car drove normally before the incident and no CEL.
To my shock, dealership quoted me a $5k repair bill including replacement of ECU and wiring harness due to the infamous camshaft magnet leak. I went to inspect the cam magnet connectors, fair enough there was a bit of oil, maybe damp, but not drenched. The ECU connectors looked dry. The STAR diagnosis report showed the ME 9.7 (ECM) module had no serial number, i.e. failure to communicate, and that other modules are showing errors like “No CAN message received from ECM”.
I’m not 100% sure if replacing the ECU is necessary as I see others have had their ECU drenched with oil and upon cleaning, car drives well with no issues. To you guys out there whom experienced this before, would cleaning the harness and connectors be sufficient? Perhaps it was just a fuse breakage caused by the electrical short? Any other suggestions are welcome. Not looking to drop $5k on the car currently.
Look forward to hearing your thoughts.
Mo420
Junior Member
Joined: Dec 2019
Posts: 18
Likes: 11
From: EU, Slovenia (top 10 destination in 2019 by Lonely Planet)
E220CDI Avantgarde SW
By my experience oil never made a short circuit and can't be the cause for fuse failure!!!
Previously bad or let say not reliable contact can loose contact when oil is present. I clean the contacts with special electronic PCB cleaner, but I think also brake cleaner can be used.
After changing some exposed pins or contacts on older cars I always protect the contacts with a gentle spray of Krown protecting oil. Such treated contacts newer failed even after many years.
Previously bad or let say not reliable contact can loose contact when oil is present. I clean the contacts with special electronic PCB cleaner, but I think also brake cleaner can be used.
After changing some exposed pins or contacts on older cars I always protect the contacts with a gentle spray of Krown protecting oil. Such treated contacts newer failed even after many years.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
When oil and ATF are non-conductors, when they leak, they pick up dirt on the way.
The issue is "famous" on 722.6 aka 5G transmissions, where pilot bushing leaks can allow ATF to run up the wire harness and flood TCU.
Lot of members opened TCU box and gave it good bath with MAF, or other cleaner with good results.
Hope it might work in this case.
The issue is "famous" on 722.6 aka 5G transmissions, where pilot bushing leaks can allow ATF to run up the wire harness and flood TCU.
Lot of members opened TCU box and gave it good bath with MAF, or other cleaner with good results.
Hope it might work in this case.
Thread Starter
Junior Member
Joined: Sep 2017
Posts: 39
Likes: 2
2011 W204 C180 GGI (FL)
Thanks for the replies folks!
Just got the car back from the dealership. Figured that I should try get my hands dirty and see what my options are before biting the $5k bullet. I plan to clean the contacts on the harness as suggested. Considering my no-cranking situation, is there any particular connector I should pay particular attention to? Would a loose camshaft magnet connection prevent the engine from cranking?
I’ve always thought the ECU is quite robust too, and small oil leaks will not necessary kill it. Hopefully I can save mine with some cleaning!
I did replace my battery as part of my initial troubleshooting. The old battery had a low voltage when I measured (I think it was 10v) and it was 4 years old already anyway. Perhaps the ESP message appeared due to this?
I clean the contacts with special electronic PCB cleaner, but I think also brake cleaner can be used.
After changing some exposed pins or contacts on older cars I always protect the contacts with a gentle spray of Krown protecting oil. Such treated contacts newer failed even after many years.
After changing some exposed pins or contacts on older cars I always protect the contacts with a gentle spray of Krown protecting oil. Such treated contacts newer failed even after many years.
I did replace my battery as part of my initial troubleshooting. The old battery had a low voltage when I measured (I think it was 10v) and it was 4 years old already anyway. Perhaps the ESP message appeared due to this?
Thread Starter
Junior Member
Joined: Sep 2017
Posts: 39
Likes: 2
2011 W204 C180 GGI (FL)
Hi all,
Just for the sake of closure, my car has been fixed now.
Opened up my original ECU to find that a few components inside were burnt beyond repair.
ECU was finally replaced at the dealership - they offerred a remanufactured unit with a slight discount. Took almost a month for parts to arrive from Germany. I did not replace my wiring harness though as I felt it was not necessary, despite the dealership insisting on it. Also, as my camshaft magnets were leaking, I replaced all 4 magnets too.
So far car runs good, however, I am still concerned that the problem may come back again in the future and still looking at permanent solutions.
Regards,
Mo420
Just for the sake of closure, my car has been fixed now.
Opened up my original ECU to find that a few components inside were burnt beyond repair.
ECU was finally replaced at the dealership - they offerred a remanufactured unit with a slight discount. Took almost a month for parts to arrive from Germany. I did not replace my wiring harness though as I felt it was not necessary, despite the dealership insisting on it. Also, as my camshaft magnets were leaking, I replaced all 4 magnets too.
So far car runs good, however, I am still concerned that the problem may come back again in the future and still looking at permanent solutions.
Regards,
Mo420
