P0091 ISUZU – Fuel Pressure Regulator Solenoid 1 Control Circuit Low Voltage

P0091 ISUZU Possible Symptoms

Engine Light ON (or Service Engine Soon Warning Light)

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)

P0091 ISUZU Description

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.