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 or P0193 00 | P0193 00 | P0191 00 |
Circuit/System Description
The fuel pump 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. |
| • | 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. |
Conditions for Setting the DTC
| • | 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. |
Action Taken When the DTC Sets
DTC P0191 is an A type DTC.
Conditions for Clearing the DTC
DTC P0191 is an A type DTC.
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
Connector End View Reference
Description and Operation
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Ignition ON, vary the engine speed with the accelerator pedal. Verify that DTC 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. |
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the fuel line pressure sensor.
- Ignition OFF, test for less than 1.0 ohm of resistance between the low reference circuit terminal 2 and ground.
- Ignition ON, test for 4.8-5.2 volts between the fuel line pressure sensor 5-volt reference circuit terminal 3 and ground.
- Ignition ON, observe the Fuel Pump Control Module Fuel Rail Pressure Sensor parameter.
- Install a 3A fused jumper wire between the 5-volt reference circuit terminal 3 and the fuel line pressure sensor signal circuit terminal 1. The scan tool should display between 4.8-5.2 volts.
- If all circuits test normal, replace the fuel rail pressure sensor.
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the fuel system control module. |
| ⇒ | 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 system 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 system control module. |
| ⇒ | If less than the specified range, test the signal circuit terminal 1 for a short to ground or an open/high resistance. If the circuit tests normal, replace the fuel system control module. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for FPCM replacement, setup, and programming |
