Transmission May Leak Fluid and Damage Control Module on Mercedes-Benz C240 4MATIC

Problem Description and Possible Solution

The electrical connector at the automatic transmission may leak fluid into the wiring harness. If not repaired, the oil will migrate through the wiring harness and damage the transmission control module. A new harness and control module may be necessary to correct this problem.

Problem Data
RepairPal Verified
Average mileage: 82,687 (12,000–121,564)
3 model years affected: 2003, 2004, 2005
16 people reported this problem
Viewing 1 - 6 of 6 comments
fluid leaked up the cable going to the tcu. Faulty boot let fluid reach the TCU, shorting it out somehow. now the Tranny won't engage and has caused physical damage requiring transmission replacement. still parked. still paying monthly storage and loan payments. Thanks MB!!
transmission went into limp mode. Dealer said fluid had got into control module.
also said that they were seeing a lot of this happen
delay in up-shift; hard shifting; my mechanic found the leak and cleaned the harness and TCU pins avoiding a replacement of the entire harness.