Kl_30 TCU power supply failure high
â–¶ How to fix
Switch off ignition; Connect terminal tester between TCU and vehicle; Switch on ignition; Measure voltage between pin 8 (VP1) and pin 17 (VM1), nominal value: < 38 V; If you find deviations from nominal value, check power supply (vehicle side);
What you'll see
No driver-visible symptom recorded.
System reaction
Activate "Central Solenoid Disconnection Unit";
Diagnostic depth
Detection
Supply voltage slowly exceeds diagnosis threshold (17 V). Fault is recognized by hardware (TCU – input wiring) and reported to software. However, not immediately after ignition on and not immediately after ignition off (negative feed from on-board electronics possible; inductivity); Normal mode
Possible cause
Transmission shifts to neutral (gear loss); Retarder is no longer available;;