For 1990-2009 cars

## DTC P0192 or P0193 ECM

### 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/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
5 V Reference Voltage | P0193, P0642 | P0193 | P0193, P0643 | P0191
FRP Sensor Signal | P0192 | P0193 | P0193 | P0191
Low Reference | -- | P0193 | P0193, P0643 | P0191

### 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

#### 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 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.

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 Ω 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 Ω 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 after completing the diagnostic procedure.

• | Fuel Pressure Sensor Replacement - Fuel Injection Fuel Rail

• | Control Module References for ECM replacement, setup, and programming

## DTC P0192 or P0193 FPCM

### 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, P0192 | P0193 | P0191
Fuel Line Pressure Sensor Low Reference | -- | P0641, P06A6 | -- | P06A6

### Circuit/System Description

The fuel pressure sensor is mounted on the fuel line. Fuel pressure is measured by the fuel pressure sensor. The fuel pump flow control module (FPCM) monitors the voltage signal from the fuel pressure sensor and also supplies the voltage and the ground of the fuel pressure sensor.

### Conditions for Running the DTC

The ignition is on.

### 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 A DTCs.

### Conditions for Clearing the DTC

DTCs P0192 and P0193 are Type A 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

1. Ignition OFF, disconnect the harness connector at the fuel line pressure sensor.
2. Ignition OFF, test for less than 1.0 ohm between the low reference circuit terminal 2 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 FPCM.

3. Ignition ON, test for 4.8-5.2 volts between the fuel line pressure sensor 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 the circuit tests normal, replace the FPCM.

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

4. Ignition ON, observe the Fuel Pump Control Module Fuel Rail Pressure Sensor parameter.
5. 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 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 FPCM.

⇒ | If greater than the specified range, test the signal circuit terminal 1 for a short to voltage. If the circuit tests normal, replace the FPCM.

6. If all circuits test normal, replace the fuel pressure sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Fuel Pressure Sensor Replacement - Fuel Feed Pipe

• | Control Module References for FPCM replacement, setup, and programming