Mercedes-Benz E300 shifts to park automatically while moving under 10 MPH, dealership unable to repair on Mercedes-Benz E300

Some Mercedes-Benz E300 owners report experiencing issues with the vehicle shifting into Park automatically while moving under 10 MPH. This problem may be caused by a defective brake light switch, which prevents the car's computer from detecting that the brake is being pressed. Additionally, low voltage or a dead battery can affect the car's electronic systems, leading to unexpected behavior such as shifting into Park. Some owners have also noted that spilled liquid on the shifter assembly can result in malfunctions, while a faulty shift interlock solenoid or issues with the engine control might contribute to this issue. Repair attempts have included replacing the Integrated Shift Module (ISM), Drive Selector Module (DSM), brake light switch, and even the battery and valve body with solenoids. However, some dealerships have struggled to resolve this issue, leaving owners with ongoing concerns. It is crucial for owners to address the root cause of this problem to prevent further instances of unintended shifting into Park. Consulting with a specialized technician may be necessary to effectively resolve this challenging issue.