P0090
Fuel Pressure Regulator A Control Circuit/Open
Open circuit at fuel pressure regulator A. The actuator that controls rail pressure cannot be driven.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Hard start, no start, or stalling under load
- Power loss especially at high load or rpm
- Possible long cranking time
Common causes
Ordered by how often each turns out to be the cause.
- Wiring break or unplugged connectorCommon
- Regulator solenoid openPossible
- Pin pushed back out of connector bodyLess likely
Parts involved
- Fuel Pressure Regulator
- Regulator Wiring
P0090 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.