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 ML500
Average mileage: 155,000 (135,000–170,000)
7 people reported this problem
2002 Mercedes-Benz ML500 135,000 mi, Visitor
ML would be driving fine and then loss of power and hard shifting. Did not fix problem yet.
2005 Mercedes-Benz ML500 170,000 mi, Visitor
I'm still looking for a solution.