P3003
ModerateP3003 — Fuel High-Pressure System Plausibility Error
Description
What the Code Means
P3003 points to a plausibility error in the fuel high-pressure system. The DME compares the rail pressure sensor signal against the lambda control readings. If the mixture adaptation shows a rich condition at low pressure or a lean condition at high pressure, the code sets. Possible causes: a faulty fuel pressure sensor, leaks in the high-pressure system, or a failed high-pressure fuel pump (HPFP).
Symptoms
Symptoms
- Rough engine running
- Mixture composition faults (rich or lean)
- Loss of power
Causes and fixes
Diagnosis and Repair
Step 1
Check the rail fuel pressure sensor with ISTA. Compare the readings against reference values.
Step 2
Check the oxygen sensors (lambda sensors) for correct operation.
Step 3
Check the high-pressure system for fuel leaks.
Step 4
Replace the faulty components (pressure sensor, HPFP, seals).
Possible secondary damage
Secondary Problems
Ignoring the fault can lead to incorrect fuel pressure control, which can damage the injectors and the catalytic converter.