P12A2

P12A2

Diagnosis information - DME (DFI)

Fuel high-pressure sensor implausible

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 permanent deviation of the measured fuel high pressure from the calculated fuel high pressure.
- The fuel high pressure value is calculated from various variables such as lambda control and fuel quantity control.

Diagnostic conditions
- Battery positive voltage more than 9 V
- Engine start recognized more than 250 sec.
- Engine temperature -10 °C ... +100 °C (50 °F ... 212 °F)
- Engine speed 450 ... 4,000 rpm
- Lambda control active

Possible fault causes
- Predelivery quantity or pressure in fuel low-pressure circuit too low
- Fuel high-pressure system leaking
- Fuel high-pressure sensor faulty
- Fuel high-pressure pump faulty