Fuel rail/system pressure is above the expected level on the DFI system.
SYMPTOMS
- Check-engine light
- Rough running
- Fuel smell
- Possible misfire
LIKELY CAUSES
- Faulty pressure regulator/control valve
- Stuck high-pressure pump
- Faulty rail pressure sensor
DIAGNOSIS STEPS
- Check commanded vs actual rail pressure
- Test the pressure regulator/control valve
- Inspect the rail pressure sensor
RELATED PARTS
- Fuel pressure regulator
- High-pressure fuel pump