P0089
DTC P0089 Fuel Pressure Regulator PerformanceCircuit Description
The common rail fuel system is comprised of two fuel pressure sections: a suction side between the fuel tank and the fuel supply pump and a high-pressure side between the fuel supply pump and the fuel injectors. Fuel is drawn from the fuel tank via a feed pump and then pumped into the fuel rail by two plungers all of which are internal to the fuel supply pump. This high pressure is regulated by the ECM using the fuel rail pressure (FRP) regulator dependant upon values from the FRP sensor attached to the fuel rail. If the ECM detects that fuel pressure is a certain pressure higher than the desired pressure this DTC will set.
Condition for Running the DTC
^ DTCs P0091 P0092 P0192 P0193 P0642 and P0643 are not set.
^ The battery voltage is between 10 to 16 volts.
^ The ignition switch is ON.
^ The engine is running.
Condition for Setting the DTC
^ The ECM detects that the actual fuel rail pressure is more than 1,450 psi (10 MPa) over the desired pressure for longer than 30 seconds.
Action Taken When the DTC Sets
^ The ECM illuminates the MIL when the diagnostic runs and fails. Refer to DTC Type Definitions for Action Taken When the DTC Sets - Type A.
^ The ECM inhibits accelerator pedal control.
^ The ECM inhibits EGR control.
^ The ECM inhibits DPF regeneration control.
^ The ECM inhibits cruise control.
^ The ECM inhibits PTO control.
Condition for Clearing the DTC
^ Refer to DTC Type Definitions for Condition for Clearing the MIL/DTC - Type A.
Diagnostic Aids
^ An intermittently sticking FRP regulator may have allowed the fuel pressure to become high enough to set this DTC.
^ Normal Actual Fuel Rail Pressure readings on the scan tool with the engine running in neutral at idle is around 3,900 to 4,800 psi (27 to 33 MPa) after warm up.
^ A skewed FRP sensor value can set this DTC. The FRP Sensor on the scan tool should read 0.9 to 1.0 volt after the engine has stopped running for a minimum of 30 seconds.
Circuit System Testing DTC P0089
