VPS short circuit to ground
Switch off ignition; Disconnect electronics incl. transmission cables; Connect transmission checking cables; Measure resistance of the supply of the proportional valves (VPS) against ground (KL 31) / housing (pin 5 and pin 3 against ground (KL31) / housing), nominal value: > 10 Mohm; Check cable TCU -> transmission; If you find deviations from nominal value, check wiring and component;
What you'll see
No driver-visible symptom recorded.
System reaction
Activate "Central Solenoid Disconnection Unit";
Diagnostic depth
The total current of all current regulators is significantly higher than theoretically necessary Readback voltage is very low (U_Vps -> 0V) Control frequency is lower than minimum permitted control frequency (f_act -> 0Hz); Current regulator incidates fault; Normal mode
Transmission shifts to neutral (gear loss); Retarder is no longer available;;