P0193

DTC P0192 or P0193

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

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

Diagnostic Fault Information






Circuit/System Description

The fuel rail pressure (FRP) sensor has a 5-volt reference circuit, a signal circuit, and a low reference circuit. The engine control module (ECM) monitors the voltage on the FRP sensor circuits. When the fuel pressure is high, the signal voltage is high. When the fuel pressure is low, the signal voltage is low. The fuel pressure regulator has a solenoid supply voltage circuit and a solenoid control circuit. The ECM controls the fuel pressure regulator, which regulates high pressure fuel that goes to the fuel injector rails and the injectors.

Conditions for Running the DTC

* The ignition is ON.
* DTCs P0652 or P0653 are not set.
* These diagnostics run continuously within the enabling conditions.

Conditions for Setting the DTC

P0192

The ECM detects the signal circuit voltage that is less than 0.254 volts for more than one second.

P0193

The ECM detects that the signal circuit voltage is more than 4.75 volts for more than one second.

Action Taken When the DTC Sets

* DTCs P0192 and P0193 are Type A DTCs.
* The ECM commands the engine to operate in the Reduced Engine Power mode.
* The message center displays Reduced Engine Power.

Conditions for Clearing the MIL/DTC

DTCs P0192 and P0193 are Type A DTCs.

Circuit/System Verification

Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

1. Verify that DTCs P0652 or P0653 are not set.

^ If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle. Diagnostic Trouble Code Descriptions

2. Observe the Fuel Rail Pressure Sensor parameter with a scan tool. During engine cranking, the pressure should be at least 10 MPa. With the engine running at idle, the pressure should be close to the Desired Fuel Rail Pressure. As the engine speed increases, the Desired Fuel Rail Pressure and the Fuel Rail Pressure Sensor should closely match each other.
3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

Important: Fuel pressure control will be disable if DTC P0087, P0088, P0192, or P0193 are set. Codes must be cleared to enable the device control.

1. Ignition OFF, disconnect the FRP sensor connector.
2. Turn ON the ignition, with the engine OFF.
3. Observe the Fuel Rail Pressure Sensor parameter with a scan tool The fuel pressure should be 200 MPa (29,000 psi).

^ If the fuel pressure is 0 MPa (0 psi), test the FRP sensor signal circuit for a short to ground. If the circuit tests normal, replace the ECM.

4. Probe the signal circuit terminal 2 with a test lamp connected to ground. The test lamp should not illuminate.

^ If the test lamp illuminates, test the signal circuit for a short to voltage.

5. Connect a fused jumper between the FRP signal circuit terminal 2 and the low reference circuit terminal 1 and observe the Fuel Rail Pressure Sensor parameter with a scan tool. The fuel pressure should be 0 MPa (0 psi).

^ If the fuel pressure does not go to 0 MPa (0 psi), test the FRP sensor signal circuit and the low reference circuit for an open. If the circuit tests normal, replace the ECM.

6. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and ground.

^ If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If all circuits test normal, replace the ECM.

^ If greater than the specified range, test the 5-volt reference circuit for a short to voltage, If the circuit tests normal, replace the ECM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Fuel Injection Fuel Rail Fuel Pressure Sensor Replacement