Return Pump Fault

Fault Code 4266

Return pump fault

Diagnostic conditions
- Return pump voltage and motor relay voltage actual values are evaluated and display implausible values
- Open circuit in electric circuit

Possible cause of fault
- Return pump motor locked up/runs too easily
- Wire/ plug connection faulty
- PSM hydraulic unit faulty

Affected terminals
PSM 5.7: Terminal 1
PSM 5.3: Terminals 7, 20

Diagnosis/troubleshooting PSM 5.7







Diagnosis/troubleshooting PSM 5.3

Part 1:

Part 2: