What the P0090 code means?
P0090 is an OBD-II code telling us there is a fault found within the fuel pressure regulator control circuit. This DTC is triggered when the ECM finds out-of-range performance from the control circuit. Out of range performance causes a Check Engine Light and a failsafe mode. Failsafe mode will remain in effect until normal sensor operation is detected or the issue is fixed.
What causes the P0090 code?
Probable causes include a defective electronic fuel pressure regulator, a faulty fuel pump, clogged fuel filter, a low fuel condition, a faulty fuel pump driver/relay, or a defective fuel rail sensor. Open, shorted, damaged, or corroded electrical wiring and/or electrical connectors are also common causes of this code being stored. Wildlife damage (to system circuitry and components) is common on this area of the engine.
What are the symptoms of the P0090 code?
1. Delayed start-up
2. Black smoke from the exhaust system
3. Diminished fuel efficiency
Common mistakes when diagnosing the P0090 code:
Often the fuel pressure regulator is replaced in error when the fuel rail sensor is defective. Techs report that many fuel pumps and other components have been replaced when a vehicle is simply out of fuel. If the fuel level gauge is not working properly, the likelihood of this misdiagnosis becomes more prominent.
What repairs can fix the P0090 code?
1. Repair of an open or short in the wiring harness
2. ECU replacement if it fails test procedures
3. Replacement of the fuel pressure regulator
4. Fixing poor electrical connections