P0089 ISUZU - Fuel Rail Pressure Performance
Faulty fuel pressure regulator
Fuel pressure regulator harness is open or shorted
Fuel pressure regulator electrical circuit poor connection
Faulty fuel pressure sensor
When is the code detected?
Fuel rail pressure greater than 1450psi over desired rate
Engine Light ON (or Service Engine Soon Warning Light)
P0089 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.