OBD-II · Engine and powertrain (P)
P0090
Fuel pressure regulator 1 control circuit/open
What it means
The ECU detects an electrical fault in the circuit that drives the fuel pressure regulator or volume control valve.
Symptoms
- reduced power or limp mode
- hesitation, jerking or misfire under load
- long cranking or hard starting
- engine may stall
- engine warning light
Likely causes, most likely first
| No. | Cause |
|---|---|
| 01 | failed regulator/control valve coil |
| 02 | open or shorted wiring |
| 03 | corroded or loose connector |
| 04 | ECU driver fault |
What to check, step by step
- 01Inspect the regulator connector and wiring for damage and corrosion
- 02Measure the regulator coil resistance and compare with specification
- 03Check the supply and ECU control wire for opens and shorts
- 04Replace the regulator (on many pumps it is part of the high-pressure pump) if it is faulty