PSM

Fault code 2231

Brake actuated signal (PSM)

NOTE: This fault code is set if a difference is detected between the analog (brake light) and digital signal (CAN data bus).

Diagnostic conditions
- Ignition on
- Internal function test on PSM control unit
- Actuate brake pedal and then release it again

Possible causes of fault
- Short circuit to B+ (electrical fault in electric circuit)
- Short circuit to ground (electrical fault in electric circuit)

Affected pins
PSM control unit:
- Up to model year '05: Pin 35 'brake light' for relay carrier/left of dashboard
- As of model year '05: Pin 35 'brake light' for 'trailer hitch control unit' and 'rear convenience system control unit'

Diagnosis/troubleshooting