Engine Controls and Fuel (ECM)
DTC P0192 or P0193 (ECM)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) 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 detects fuel pressure within the fuel rail. The engine control module (ECM) provides a 5-volt reference voltage on the 5-volt reference circuit and ground on the reference ground circuit. The ECM receives a varying signal voltage on the signal circuit. The 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.
Conditions for Running the DTC
* The ignition is ON or the engine is running.
* The DTCs run continuously within the enabling conditions.
Conditions for Setting the DTC
P0192
The ECM detects that the signal circuit voltage is less than 0.3 volt for greater than 4 seconds.
P0193
The ECM detects that the signal circuit voltage is greater than 4.7 volts for greater than 4 seconds.
Action Taken When the DTC Sets
* DTCs P0192 and P0193 are Type A DTCs.
* A message center or an indicator may display Reduced Engine Power.
Conditions for Clearing the DTC
DTCs P0192 and P0193 are Type A DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Fuel System Description (Fuel System Description)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Ignition ON, observe the DTC information with a scan tool, DTC P0641, P0642, or P0643 should not be set.
• If a DTC is set, refer to DTC P0641-P0643, P0651-P0653, or P0697-P0699 (P0641).
2. Engine idling, observe the DTC information with a scan tool. DTC P0192 or P0193 should not set.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
1. Ignition OFF, disconnect the multi-way harness connector X117 at the rear of the intake manifold.
2. Remove the fuse that supplies B+ to terminal 56-X2 of the ECM.
Note: Testing for steps 3 through 7 is performed on the ECM side of the multi-way harness connector.
3. Ignition OFF, test for less than 5 ohm between the low reference circuit terminal 5 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
4. Install the fuse that supplies B+ to terminal 56-X2 of the ECM.
5. Ignition ON, test for 4.8-5.2 V between the 5-volt reference circuit terminal 11 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 the circuit tests 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.
6. Ignition ON, verify the scan tool FRP sensor voltage parameter is greater than 4.96 V.
• If less than the specified value, test the signal circuit terminal 12 for a short to ground. If the circuit tests normal, replace the ECM.
7. Connect a 3 A fused jumper wire between the signal circuit terminal 12 and the low reference circuit terminal 5. Verify the scan tool FRP voltage parameter transitions from greater than 4.96 V to less than 0.02 V.
• If the parameter does not transition from the maximum to minimum value, test the signal circuit for an open/high resistance or a short to voltage. If the circuit tests normal, replace the ECM.
8. Ignition OFF, remove the intake manifold.
9. Connect the multi-way harness connector X117.
Note: Testing for steps 11 through 15 are performed at the FRP sensor connector.
10. Disconnect the FRP sensor connector.
11. Remove the fuse that supplies B+ to terminal 56-X2 of the ECM.
12. Ignition OFF, test for less than 5 ohm between the low reference circuit terminal 1 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance.
13. Install the fuse that supplies B+ to terminal 56-X2 of the ECM.
14. Ignition ON, test for 4.8-5.2 V 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 greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
15. Ignition ON, verify the scan tool FRP sensor voltage parameter is greater than 4.96 V.
• If less than the specified value, test the signal circuit terminal 2 for a short to ground.
16. Connect a 3 A fused jumper wire between the signal circuit terminal 2 and the low reference circuit terminal 1. Verify the scan tool FRP voltage parameter transitions from greater than 4.96 V to less than 0.02 V.
• If the parameter does not transition from the maximum to the minimum value, test the signal circuit for an open/high resistance or a short to voltage.
17. If all circuits test normal, replace the FRP sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Fuel Pressure Sensor Replacement - Fuel Injection Fuel Rail (Fuel Pressure Sensor Replacement - Fuel Injection Fuel Rail)
* Control Module References (Programming and Relearning) for ECM replacement, setup, and programming