Retarder lever sensor short circuit to ground.
â–¶ How to fix
• Check the connectors and wiring • Check the control lever. • Measure the sensor voltage between signal and ground.
What you'll see
No driver-visible symptom recorded.
System reaction
Manual retarder brake will not function as long as the fault is present.
Diagnostic depth
Detection
Impermissible signal from the control lever for auxiliary brake control. The sensor voltage level too low. The auxiliary brake lever sensor is short circuit to ground.
Possible cause
• Short circuit to ground on retarder lever signal (pin A5) • Faulty control lever unit • Faulty connectors.