P1021

P1021

Diagnosis information - DME V8 DFI

Fuel high-pressure quantity

NOTE:
- Faults in the fuel high-pressure injection area are often caused by defects in the predelivery circuit (fuel low-pressure).
- Therefore, if there are problems. In the fuel high-pressure injection area, the predelivery circuit must be checked first.

NOTE: Diagnosis detects a deviation between setpoint and actual values in fuel high-pressure quantity control.

Diagnostic conditions
- Battery positive voltage > 9 V
- Engine speed between 450 rpm and 4000 rpm
- Engine temperature - 10 °C ...+ 100 °C (50 °F ... 212 °F)
- Drive with different load and speed ranges

Possible fault causes
- Predelivery quantity or pressure in fuel low-pressure circuit too low
- Quantity control valve faulty (in fuel high-pressure pump)
- Fuel high-pressure pump faulty