Retarder manual lever illegal voltage level.
â–¶ How to fix
• Check the retarder lever. • Measure the sensor voltage between signal and ground. • Check the connectors and wiring
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 manual retarder brake control. The sensor voltage level does not correspond to a valid lever position. The retarder lever sensor is faulty.
Possible cause
• Defect retarder lever unit • Defect connectors • Defect wiring