P1023
P1023Diagnosis information - Control unit DME (DFI)
Fuel pressure/quantity too low at start
INFORMATION
- This fault entry can be caused by diverse reasons.
- Fault finding is to be performed only if a customer complains about excessively long starting times.
- If there is no such customer complaint, the only measure to be taken is to clear the fault memory.
Diagnostic conditions
- Engine start
- Engine temperature -10 ... +100 °C (°F)
- Engine running > 5 Second(s)
Possible fault causes
- Pre-delivery quantity or pressure in fuel low-pressure circuit too low (See [Information] 1)
- Quantity control valve Faulty (in Fuel high-pressure pump)
- Fuel high-pressure pump Faulty
Fault setting condition(s)
- Low-pressure start enabled (See [Information] 2)
INFORMATION
1. - Faults in the fuel high-pressure injection system are often caused by defects in the preFaults Pre-delivery system (fuel low pressure).
- Therefore, if there are problems in the fuel high-pressure injection area, the Pre-delivery circuit must be checked first.
2. - Starting in the low-pressure range is enabled if the required fuel pressure for a high high-pressure start was not reached or was not reached quickly enough. pressure
- Starting takes considerably longer (up to 2 sec.) as a result.