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 P0191 00: Fuel Rail Pressure (FRP) Sensor PerformanceDiagnostic Fault Information
Circuit | Short to Ground | Open or High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Fuel Rail Pressure (FRP) Sensor Signal | P0192 00 | P0191 00, P0193 00 | P0193 00 | P0191 00 |
Circuit/System Description
The fuel pump flow control module (FPCM) monitors the voltage signal from the fuel pressure sensor. This DTC will set if the FPCM detects a stuck fuel pressure sensor signal.
Conditions for Running the DTC
| • | The engine is running. |
| • | DTC P0192, P0193, 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. |
| • | The engine has been running for at least 5 seconds. |
Conditions for Setting the DTC
The FPCM does not detect a change in the FRP of at least 30 kPa (4.4 psi) over a predetermined variance of the engine speed.
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will illuminate. |
| • | The FPCM records the operating conditions at the time the diagnostic fails. The FPCM stores this information in the Failure Records. |
Conditions for Clearing the DTC
| • | A last test failed, or the current DTC, clears when the diagnostic runs and does not fail. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if failures are not reported by this or any other emission related diagnostic. |
Diagnostic Aids
| • | A near empty or empty fuel tank may set this code as current or in history. |
| • | 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
Connector End View Reference
Engine Controls Connector End Views
Description and Operation
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
Important: Repair all other driveability DTCs or problems before performing this diagnostic.
Engine ON with the engine idling at normal operating temperature, the Fuel Rail Pressure Sensor parameter should read between 296.4 - 310.3 kPa (43 - 45 psi).
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.
- Engine ON, vary the engine speed with the accelerator pedal. Verify that P0191 does not set as current.
- If the DTC does not reset in the FPCM, the system is OK. Do not replace the FPCM.
| ⇒ | If the DTC sets as current, test the fuel line pressure sensor signal circuit for a high resistance. If the circuit tests normal, replace the fuel line pressure sensor. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
