Maybe you know this already but just in case....
In my major last service (W140L-S320), I had to replace the plug that joins the gearbox to the Engine Control Unit (ECU) at the gearbox end. This was because the plug seal had gone and was leaking a small amount of transmission fluid onto the floor. Whilst surfing the other forums at the time, I found some horror stories of ECUs flooding with transmission fluid as a result of this problem. Anyway, mine was changed, no problem.
I've just been back to my friendly local specialist who has a S280 in the garage with an ECU plug problem. His is more serious than mine ever was.. The plug seal had perished in such a way that the fluid was not leaking externally, but was forcing itself up inside the wiring until it reached the ECU. Now the ECU sits higher than the gearbox plug but the fluid still manages to travel up the wire?! The ECU has taken on a considerable amount of fluid and has ceased to work - putting the gearbox into 1st gear only - limp home mode I guess. The ECU has been removed and I've just seen the transmission fluid being poured (yes poured!) out of it. To replace it is £300 for the part.
The moral of this story is to have your ECU plug renewed where it joins the gearbox. I think that the transmission fluid will need to be renewed at the same time but that's no bad thing either. The ECU plug is just a few pounds. The cost of not having it done, could be huge.
One of the other boards has picture postings of the problem, along with a replacement warning.
Regards,
John
In my major last service (W140L-S320), I had to replace the plug that joins the gearbox to the Engine Control Unit (ECU) at the gearbox end. This was because the plug seal had gone and was leaking a small amount of transmission fluid onto the floor. Whilst surfing the other forums at the time, I found some horror stories of ECUs flooding with transmission fluid as a result of this problem. Anyway, mine was changed, no problem.
I've just been back to my friendly local specialist who has a S280 in the garage with an ECU plug problem. His is more serious than mine ever was.. The plug seal had perished in such a way that the fluid was not leaking externally, but was forcing itself up inside the wiring until it reached the ECU. Now the ECU sits higher than the gearbox plug but the fluid still manages to travel up the wire?! The ECU has taken on a considerable amount of fluid and has ceased to work - putting the gearbox into 1st gear only - limp home mode I guess. The ECU has been removed and I've just seen the transmission fluid being poured (yes poured!) out of it. To replace it is £300 for the part.
The moral of this story is to have your ECU plug renewed where it joins the gearbox. I think that the transmission fluid will need to be renewed at the same time but that's no bad thing either. The ECU plug is just a few pounds. The cost of not having it done, could be huge.
One of the other boards has picture postings of the problem, along with a replacement warning.
Regards,
John
