Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC P0089: Fuel Pressure Regulator PerformanceDiagnostic Fault Information
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Fuel Rail Pressure Sensor 5-Volt Reference Circuit | P0192, P02E8, P0409, P0462, P0642, P2453, P2454, P2564 | P0192 | -- |
Fuel Rail Pressure Sensor Signal Circuit 1 | P0192 | P0193 | P0193 |
Fuel Rail Pressure Sensor Signal Circuit 2 | P0192 | P0193 | P0193 |
Fuel Rail Pressure Sensor Signal Circuit 1 and 2 | P0192 | P0193 | P0193 |
Fuel Rail Pressure Sensor Ground Circuit | -- | P0193 | -- |
Typical Scan Tool Data
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Operating Conditions: Engine Running Parameter Normal Range: 25 MPa | |||
Fuel Rail Pressure Sensor 5-Volt Reference Circuit | 0.0 MPa | 0.0 MPa | -- |
Fuel Rail Pressure Sensor Signal Circuit 1 | 0.0 MPa | 246.6 MPa | 246.6 MPa |
Fuel Rail Pressure Sensor Signal Circuit 2 | 0.0 MPa | 246.6 MPa | 246.6 MPa |
Fuel Rail Pressure Sensor Signal Circuit 1 and 2 | 0.0 MPa | 246.6 MPa | 246.6 MPa |
Fuel Rail Pressure Sensor Ground Circuit | -- | 246.6 MPa | -- |
Circuit/System 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, 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 engine control module (ECM) using the fuel rail pressure (FRP) regulator, dependant upon values from the FRP sensor attached to the fuel rail. In case of fuel rail overpressure, a pressure limiter valve threaded into the fuel rail will open to release overpressure and return fuel back to the fuel tank.
Conditions for Running the DTC
| • | DTCs P0091, P0092, P0192, P0193, P0642 and P0643 are not set. |
| • | The battery voltage is between 10-16 volts. |
| • | The ignition is ON for longer than 2 seconds. |
| • | The injectors are operating. |
Conditions for Setting the DTC
The ECM detects that the actual fuel rail pressure is higher than desired pressure 10 MPa for longer than 30 seconds when commanded fuel supply is OFF.
Action Taken When the DTC Sets
| • | DTC P0089 is a Type A DTC. |
| • | The malfunction indicator lamp (MIL) is illuminated. |
| • | The ECM records Freeze Frame data. |
Conditions for Clearing the DTC
| • | DTC P0089 is a Type A DTC. |
| • | The ECM turns OFF the MIL after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Diagnostic Aids
| • | An incorrectly installed fuel rail pressure (FRP) regulator or fuel system will cause this DTC to set. |
| • | Air in fuel line will cause this DTC to set. |
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Verify the integrity of the fuel system and fuel rail pressure sensor by inspecting for the following conditions:
| • | Damaged components |
| • | Loose or improper installation |
Circuit/System Testing
Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
- Start the engine and operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
- Observe the Actual Fuel Pressure parameter with a scan tool. The actual pressure should be 0 MPa with the engine not running at operating temperature.
- Observe the Actual Fuel Pressure parameter with a scan tool. The actual pressure should be 25 MPa with the engine idling at operating temperature.
- Change the fuel pressure with a scan tool, incrementing through the entire fuel pressure range. The fuel pressure should increment and stabilize through the entire fuel pressure range, with the actual and desired fuel pressure within 2 MPa of each other.
- Test the fuel pressure regulator (FPR) solenoid control circuit and the FPR solenoid supply voltage circuit for high resistance.
| ⇒ | If the pressure difference between the actual and desired pressure are more than 2 MPa, replace the fuel rail pressure sensor. |
| ⇒ | If the pressure difference between the actual and desired pressure are more than 2 MPa , replace the fuel pressure regulator. |
| ⇒ | If all circuits test normal, refer to Diagnostic Aids. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for ECM replacement, setup, and programming |
