P0091 ISUZU - Fuel Pressure Regulator Solenoid 1 Control Circuit Low Voltage
P0091 Isuzu Possible Causes
- Faulty fuel pressure sensor
- Fuel pressure sensor harness is open or shorted
- Fuel pressure sensor electrical circuit poor connection
- Faulty Engine Control Module (ECM)
When is the code detected?
Fuel Pressure Regulator (FRP) feedback current less than 400mA
P0091 Isuzu Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P0091 Isuzu Meaning
The Engine Control Module (ECM
) uses commanded fuel pump flow to determine a desired fuel rail pressure. The actual fuel pressure is monitored using the Fuel Rail Pressure (FRP) Sensor.