P0767 Fault Code in Mercedes: Causes, Symptoms, and Fixes

Your vehicle’s Transmission Control Module (TCM) has detected that Shift Solenoid D is stuck in the ON (activated) position. This solenoid controls the flow of transmission fluid to specific hydraulic circuits, which engage certain gears. If it’s stuck ON, the transmission may be locked into or skip certain gears.

Possible Causes

1. Shift Solenoid D stuck mechanically due to debris or wear
2. Short to power in solenoid wiring (keeps it energized)
3. Faulty TCM sending constant ON signal
4. Dirty or burnt transmission fluid
5. Valve body internal blockage
6. Wiring harness damage (rubbed, melted, corroded)

Symptoms

1. Harsh or erratic shifting
2. Stuck in a single gear or “limp mode”
3. Poor acceleration
4. Check Engine Light or Transmission Warning Light
5. Increased transmission temperature

Common Fixes

1. Check transmission fluid — level, color, smell; replace if dirty/burnt
2. Inspect wiring & connectors to the solenoid for shorts or corrosion
3. Test solenoid D for proper resistance (spec varies by transmission)
4. Clean or replace valve body if debris is present
5. Replace solenoid D if it fails testing
6. Check TCM output to confirm it’s not constantly commanding ON when it shouldn’t