Central cut-off unit (ZAE) no longer cuts off
â–¶ How to fix
Check the TCU;
What you'll see
No driver-visible symptom recorded.
System reaction
Activate "Central Solenoid Disconnection Unit";
Diagnostic depth
Detection
The central switch-off relay is closed and briefly opened again during initialization of the control unit. If the condition does not change, there is a fault.; Only on directly after ignition
Possible cause
Transmission shifts to neutral (gear loss); Retarder is no longer available;;