GM Service Manual Online
For 1990-2009 cars only

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 P0192: Fuel Rail Pressure (FRP) Sensor Circuit Low Voltage

DTC P0193: Fuel Rail Pressure (FRP) Sensor Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open or High Resistance

Short to Voltage

Signal Performance

5-Volt Reference

P0641

P0641, P06A6

P0641

P06A6

Fuel Rail Pressure (FRP) Sensor Signal

P0192

P0191, P0193

P0193

P0191

Fuel Line Pressure Sensor Low Reference

--

P0641, P06A6

--

P06A6

Circuit/System Description

The fuel pressure sensor is located on the fuel line. The fuel pressure sensor monitors the fuel pressure in the fuel line. The fuel pump flow control module (FPCM) monitors the voltage signal from the fuel pressure sensor.

Conditions for Running the DTC

    • The engine is running and the fuel pressure is within normal operating range.
    •  DTC P0231, P0232, P023F, P064A, P1255 or P06A6 are not active.
    • DTC P0641 has not failed this ignition cycle.
    • Fuel pump control is enabled and the fuel pump control state is normal.

Conditions for Setting the DTC

The FPCM detects that the fuel rail pressure (FRP) sensor signal circuit is above 4.9V or below 0.1V.

Action Taken When the DTC Sets

DTCs P0192 and P0193 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0192 and P0193 are Type B DTCs.

Diagnostic Aids

Using the Failure Records data may help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine how many ignition cycles that the diagnostic test reported a pass and/or a fail.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Fuel System Description

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

Important: Verify that the fuel tank is not empty. Only perform this diagnostic if there is at least 2 gallons of fuel in the fuel tank.

  1. Ignition OFF, disconnect the harness connector at the fuel line pressure sensor.
  2. Ignition OFF, test for less than 1 ohm between the low reference circuit terminal 2 and ground.
  3. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the fuel pump flow control module.
  4. Ignition ON, test for 4.8-5.2 volts between the fuel line pressure sensor 5-volt reference circuit terminal 3 and ground.
  5. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the fuel pump flow control module.
    If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the fuel pump flow control module.
  6. Verify the scan tool 5 volt reference is less than 1 volt.
  7. If greater than the specified range, test the signal circuit terminal 1 for a short to voltage. If the circuit tests normal, replace the fuel pump flow control module.
  8. Install a 3A fused jumper wire between the signal circuit terminal 1 and the 5-volt reference circuit terminal 3. Verify the scan tool 5 volt reference is greater than 4.8 volts.
  9. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the fuel pump flow control module.
  10. If all circuits test normal, replace the fuel rail pressure sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Fuel Pressure Sensor Replacement
    •  Control Module References for FPCM replacement, setup, and programming