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. At that point, a new harness and control module may be necessary to correct this problem.
Transmission May Leak Fluid and Damage Control Module on Mercedes-Benz S600
Average mileage: 97,000 (76,000–112,000)
17 people reported this problem
2003 Mercedes-Benz S600 76,000 mi, Visitor
Transmission wouldn't go over second gear, Electrical plug leaked oil back into harness, back to Dealer (again $$$$) but repair lasted 1000 miles so "I" had to replace the speed sensor plate and now back to normal shifting!
My transmission conductor plate had this exact problem. I bought the car at 100,000 miles and after noticing the transmission clunking into certain gears and it getting stuck in a certain gear after rapid acceleration, I took it to the shop and it turns out that the gasket sealing the transmission had gone bad and fluid leaked onto the conductor plate and caused it to start to malfunction. The dealership quoted $2040 to fix it. I had another high end foreign car mechanic shop fix it for around $700. Update: 10/2015- This problem was corrected, or so I thought, and the car was running fine. Come to find out it was done wrong and I had to have the entire transmission plus the torque converter replaced, a whopping $5800. Have this diagnosed and done by a Mercedes-Benz dealer ONLY.
2003 Mercedes-Benz S600 112,000 mi, Visitor
Replaced gasket, conector, cleaned TCU with electric cleaner
This problem happened three times. The transmission control unit filled with fluid from leaking ETC connector. The Solution: They replaced control unit, locking pin, ETC connector plug, pilot bushing, trans.fluid