P0092
DTC P0090, P0091, or P0092
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions 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 hi 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 hi circuit driver pulse-width modulates (PWM) the hi circuit. The ECM monitors the voltage on the circuits to detect a failure.
Conditions for Running the DTC
* The ignition 1 signal parameter is between 6-18.1 volts.
* The DTCs run continuously within the enabling condition.
Conditions for Setting the DTC
P0090
* The fuel pressure regulator voltage is between 1-4.5 volts with the fuel pressure regulator commanded OFF.
* The above condition is present for more than 4 seconds.
P0091
* The fuel pressure regulator voltage is less than 1 volt with the fuel pressure regulator commanded OFF.
* The above condition is present for more than 4 seconds
P0092
* The fuel pressure regulator voltage is more than 4.5 volts with the fuel pressure regulator commanded ON.
* The above condition is present for more 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.
Circuit/System Verification
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). With the engine running at idle, the Actual Fuel Rail Pressure should be close to the Desired Fuel Rail Pressure. As the engine speed increases, the Desired Fuel Rail Pressure and the Actual Fuel Rail Pressure should closely match each other.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the high pressure fuel pump.
2. Engine cranking, verify that a test lamp flashes between the FRP regulator low circuit terminal 1 and B+.
• If the test lamp is always ON, test the FRP regulator low circuit for a short to ground. If the circuit tests normal, replace the ECM.
• If the test lamp is always OFF, test the FRP regulator low circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
3. Ignition ON, verify that a test lamp illuminates between the FRP regulator hi circuit terminal 2 and ground.
• If the test lamp does not illuminate, test the FRP regulator hi circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
4. Connect a test lamp between FRP regulator low circuit terminal 1 and FRP regulator hi circuit terminal 2.
5. Command the Fuel Pressure Control to Increase/Decrease with a scan tool. The test lamp should turn ON when commanding the Increase/Decrease states.
• If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuits test normal, replace the ECM.
6. If all circuits test normal, test or replace the high pressure fuel pump.
Component Testing
Static Test
1. Ignition OFF, disconnect the harness connector at the high pressure fuel pump.
2. Test for 0.49 ohm ± 0.023 ohm at 20°C (68°F) of resistance between FRP regulator low circuit terminal 1 and FRP regulator hi circuit terminal 2.
• If not within the specified range, replace the high pressure fuel pump.
3. Test for infinite resistance between each terminal and the high pressure fuel pump housing/case.
• If not the specified value, replace the high pressure fuel pump.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests
* Refer to Programming and Relearning for ECM setup and programming. Programming and Relearning
* High Pressure Fuel Pump Replacement