The electrical connector at the automatic transmission may leak fluid. Over time leaking fluid could migrate through the wiring harness and damage the transmission control module. If that happens a new harness and control module may be necessary to correct the problem.
Transmission May Leak Fluid and Damage Control Module on Mercedes-Benz S430
Average mileage: 96,333 (22,000–150,000)
16 people reported this problem
2006 Mercedes-Benz S430 22,000 mi, Visitor
MY TRANSMISSION FOR S430 ENGINE IS TO SLOW BEFORE CHANGE TO THE SECOND SPEED ONLY ON THE MORNING OR AFTER 10 OR MORE HOURS WITH OUT WORK
2002 Mercedes-Benz S430 85,000 mi, Visitor
I had the same problem with the TCM. I had the conductor plate replaced and the TCM was cleaned of all oil. After that, the transmission worked fine but the ESP, ABS, SRS, and BAS lights continue to stay on. The vehicle is in the shop now (again) to correct this problem with the malfunctions.
2003 Mercedes-Benz S430 150,000 mi, Visitor
Brought car in for service for another issue and mechanic told me transmission was leaking and traveled through wiring harness to control module. Leaking part was replaced, control module was cleaned.
2002 Mercedes-Benz S430 108,000 mi, Visitor
Just had the transmission control module replaced by the dealer. Wasn't cheap, $955.00 including parts and labor.
2000 Mercedes-Benz S430 73,000 mi, Visitor
leaking transmission by the plug,so now i am going to change fluid along with the plug when i purchase it
TRANSMISSION IS LEAKING FLUID GOT VEHICLE DIAGNOSE TO BE TOLD THAT CONNECTOR IS LEAKING HAVING IT FIX - KNOWING ITS GONNA BE EXPENSIVE
2000 Mercedes-Benz S430 79,000 mi, Visitor
I have the same problem and car has been in the shop for over 6 weeks. Really