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 Descriptors
DTC P0091: Fuel Pressure Regulator Solenoid Control Circuit Low VoltageDTC P0092: Fuel Pressure Regulator Solenoid Control Circuit High Voltage
Diagnostic Fault Information
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Fuel Rail Pressure Sensor 5-Volt Reference Circuit | P0192, P0642 | 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 fuel rail pressure (FRP) regulator is installed to the fuel supply pump and controls the suction fuel quantity into the fuel rail. The FRP regulator is fully opened in the normal state and larger drive current results in smaller opening. The engine control module (ECM) calculates desired fuel rail pressure and fuel flow rate and it compares the calculated desired fuel rail pressure to the actual value to determine the FRP regulator position. When the actual fuel rail pressure is higher than the desired value, the FRP regulator is closed to decease the flow rate.
Conditions for Running the DTC
P0091
| • | DTCs P0092, P0642 and P0643 are not set. |
| • | The battery voltage is between 10-16 volts. |
| • | The ignition switch is ON. |
| • | The FRP regulator pump control is stable. |
P0092
| • | DTCs P0091, P0642, and P0643 are not set. |
| • | The battery voltage is between 10-16 volts. |
| • | The ignition switch is ON. |
| • | The FRP regulator pump control is stable. |
Conditions for Setting the DTC
P0091
The ECM detects that the FRP regulator solenoid drive current is less than 400 mA when the drive duty cycle is more than 70 percent.
P0092
The ECM detects that the FRP regulator solenoid drive current is more than 2700 mA when the drive duty cycle is less than 20 percent.
Action Taken When the DTC Sets
DTCs P0091 and P0092 are Type A DTCs.
Conditions for Clearing the DTC
DTCs P0091 and P0092 are Type A DTCs.
Diagnostic Aids
Inspect for any recent engine mechanical repairs. An incorrectly installed fuel rail pressure (FRP) sensor 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
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.
- Ignition OFF, disconnect the harness connector at the fuel rail pressure (FRP) regulator.
- Ignition OFF, disconnect the harness connector at the control module.
- Install a 3-amp fused jumper wire between the FRP regulator circuits.
- Ignition ON, verify that a test lamp does not illuminate between the FRP regulator circuits and ground.
- Connect the regulator, ignition OFF, test for between 1.9-2.3 ohms of resistance between FRP regulator circuits at the ECM connector.
- Ignition OFF, test for between 1.9-2.3 ohms of resistance between FRP regulator terminals.
| ⇒ | If the test lamp does illuminate, test the FRP regulator circuits for a short to battery voltage. |
| ⇒ | If the resistance is more than 2 ohms or less than 1.8 ohms, test the FRP regulator for an open/high resistance. If the circuit tests normal, replace the ECM. |
| ⇒ | If resistance is more than 2 ohms or less than 1.8 ohms at 20°C (68°F), test the FRP regulator for an open/high resistance. If the circuit tests normal, replace the FRP regulator. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for ECM replacement, setup, and programming |
