P0092
DTC P0090, P0091, or P0092
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0090
- Fuel Pressure Regulator Control Circuit
DTC P0091
- Fuel Pressure Regulator Solenoid 1 Control Circuit Low Voltage
DTC P0092
- Fuel Pressure Regulator Solenoid 1 Control Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
High pressure fuel is regulated by the fuel rail pressure (FRP) regulator, which is a part of the high pressure fuel pump. The FRP regulator is a solenoid valve. The ECM provides battery voltage on the FRP regulator high circuit and ground on the FRP regulator low circuit. Both circuits are controlled through output drivers within the ECM. When deactivated, both drivers are disabled. When activated, the FRP regulator low circuit driver connects the low circuit to ground and the FRP regulator high circuit driver pulse-width modulates (PWM) the high circuit. The ECM monitors the voltage on the circuits to detect a failure.
Conditions for Running the DTC
* The ignition voltage is between 6-18 volts.
* DTCs P0090, P0091, and P0092 run continuously.
Conditions for Setting the DTC
P0090
* The fuel pressure regulator voltage is between 2.7-4.5 volts with the fuel pressure regulator is commanded ON or OFF.
* The above condition is present for greater than 4 seconds.
P0091
* The fuel pressure regulator voltage is less than 2.7 volts with the fuel pressure regulator commanded OFF.
* The above condition is present for greater than 4 seconds.
P0092
* The fuel pressure regulator voltage is greater than 4.5 volts with the fuel pressure regulator commanded ON.
* The above condition is present for greater than 4 seconds.
Action Taken When the DTC Sets
* DTCs P0090, P0091, and P0092 are Type A DTCs.
* A message center or an indicator displays Reduced Engine Power.
Conditions for Clearing the DTC
DTCs P0090, P0091, and P0092 are Type A DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Fuel System Description (Fuel System Description)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Engine idling, observe the Actual Fuel Rail Pressure parameter with a scan tool. The pressure should be approximately 3.5-5.5 Mpa (508-798 psi).
2. Command an increase and decrease in fuel rail pressure with a scan tool. Observe the scan tool Actual Fuel Rail Pressure parameter. The Actual Fuel Rail Pressure should increase or decrease with each command.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
1. Ignition OFF, open the hood to disable the Auto-Stop function.
2. Ignition ON, verify the scan tool hood position parameter displays Open.
• If the hood position does not display Open, refer to DTC P254F (P254F).
3. Ignition OFF, disconnect the harness connector X1 at the ECM.
4. Probe the FRP regulator ignition voltage circuit terminal X1-5 at the ECM harness connector with a test lamp connected to B+. Verify the test lamp does not illuminate.
• If the test lamp illuminates, test the ignition voltage circuit, and control circuit for a short to ground. If the circuits test normal, replace the high pressure fuel pump.
5. Test for less than 2 ohm between the FRP regulator ignition voltage circuit terminal X1-5, and the FRP regulator control circuit terminal X1-73 at the ECM harness connector.
• If greater than the specified range, test the ignition voltage circuit, and control circuit for an open/high resistance. If the circuits test normal, replace the high pressure fuel pump.
6. Ignition ON, test for less than 1 V between the FRP regulator ignition voltage circuit terminal X1-5 and ground.
• If greater than the specified range, test the ignition voltage circuit, and control circuit for a short to voltage.
7. If all circuits test normal, replace the ECM.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Control Module References (Programming and Relearning) for ECM replacement, setup, and programming
* Fuel Pump Replacement (Service and Repair)