P0090
Fuel Pressure Regulator A Control Circuit/Open
Fuel pressure control
Generic OBD-II
High
What it means
P0090 means the ECM has detected an electrical fault — often an open — in the control circuit for the fuel pressure regulator. That regulator sets the pressure feeding the injectors, so when the ECM can't command it the engine may hard-start, stall, or run poorly. It's a fuel-delivery fault worth diagnosing before you rely on the car.
High
Can I keep driving? Not reliably — with the ECM unable to control fuel pressure the engine can run poorly, stall, or fail to start; get it fixed before depending on it.
Common symptoms
What you'll notice
- Check-engine light on
- Hard starting or a no-start
- Rough running, hesitation, or stalling
- Reduced power and worse fuel economy
Common causes
Most likely first
- Faulty fuel pressure regulator or its control solenoidLikely
- Open, shorted, or damaged wiring in the regulator control circuitCommon
- Loose or corroded connector at the regulatorCommon
- Rarely, a faulty ECM driver for the circuitLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data, then inspect the regulator's connector and wiring for opens, shorts, and corrosion.
- Check the control circuit for the correct voltage and ground from the ECM back to the regulator.
- Test the fuel pressure regulator / control solenoid and confirm actual fuel pressure against spec.
- Repair wiring or replace the regulator as indicated; consider the ECM driver only after the circuit is verified good.
FAQ
Quick answers
Is it safe to drive with P0090?+
No, not reliably. Without proper fuel-pressure control the engine can stall or refuse to start, and pressure that's off in either direction risks poor running. Diagnose it before driving.
Can I just clear P0090?+
It comes right back — this is a circuit fault, so the ECM re-detects it. The wiring or regulator has to be repaired.
Related codes
Often seen with P0090
Read & clear P0090 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX