For 1990-2009 cars

### 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 P0190 03: Fuel Rail Pressure (FRP) Sensor Circuit Voltage Below Threshold
DTC P0190 07: Fuel Rail Pressure (FRP) Sensor Circuit Voltage Above Threshold
DTC P0190 11: Fuel Rail Pressure (FRP) Sensor Circuit Voltage Above Maximum Threshold
DTC P0190 12: Fuel Rail Pressure (FRP) Sensor Circuit Voltage Below Minimum Threshold
DTC P0191: Fuel Rail Pressure (FRP) Sensor Performance
DTC P0192: Fuel Rail Pressure (FRP) Sensor Circuit Low Voltage
DTC P0193: Fuel Rail Pressure (FRP) Sensor Circuit High Voltage

### Circuit/System Description

The fuel rail pressure (FRP) sensor measures the fuel pressure within the fuel rail. The engine control module (ECM) monitors the voltage on the FRP sensor circuits. When the fuel pressure is low, the signal voltage is low. When the fuel pressure is high, the signal voltage is high. The ECM supplies 5 volts to the 5-volt reference circuit and a ground to the low reference circuit. The FRP sensor provides a signal voltage to the ECM, relative to the pressure changes within the fuel rail, on the FRP sensor signal circuit.

### Conditions for Running the DTC

• | The ignition is ON or the engine is operating.

• | The DTCs run continuously once the above condition is met.

### Conditions for Setting the DTC

#### P0190 03, P0190 07, P0191

The ECM detects that the fuel pressure sensor voltage is less than 0.46 volts, or greater than 0.72 volts for 2 seconds.

#### P0190 12 or P0192

The ECM detects that the fuel pressure sensor voltage is less than 0.254 volt for 0.5 seconds.

#### P0190 11 or P0193

The ECM detects that the fuel pressure sensor voltage is greater than 4.7 volt for 0.5 seconds.

### Action Taken When the DTC Sets

DTCs P0190, P0191, P0192, and P0193 are Type B DTCs.

### Conditions for Clearing the DTC

DTCs P0190, P0191, P0192, and P0193 are Type B DTCs.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

• | Engine Control Module Connector End Views

• | Engine Controls Connector End Views

#### 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

• | Scan Tool Data List

• | Scan Tool Data Definitions

• | Scan Tool Output Controls

### Circuit/System Verification

1. Ignition On, observe the DTC information with a scan tool. DTCs P0651, P0652, or P0653 should not be set.

⇒ | If DTC P0651, P0652, or P0653 are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

2. Observe the scan tool Fuel Rail Pressure Sensor voltage parameter. The reading should be between 0.5 and 4.5 volts.
3. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records List.

### Circuit/System Testing

1. Ignition OFF, and the MAIN fuse removed, disconnect the harness connector at the fuel rail pressure sensor.
2. Test for less than 1.0 ohm of resistance 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. If the circuit/connections test normal, replace the ECM.

3. Install the MAIN fuse. 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 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/connections test normal, replace the ECM.

4. Verify the scan tool Fuel Rail Pressure Sensor voltage parameter is greater than 4.8 volts.

⇒ | If less than the specified range, test the signal circuit terminal 2 for a short to ground. If the circuit/connections test normal, replace the ECM.

5. Install a 3A fused jumper wire between the signal circuit terminal 2 and ground. Verify the scan tool Fuel Rail Pressure Sensor voltage parameter is less than 0.5 volts.

⇒ | If greater than the specified range, test the signal circuit for short to voltage or an open/high resistance. If the circuit/connections test normal, replace the ECM.

6. If all circuits test normal, test or replace the Fuel Rail Pressure Sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Fuel Injection Fuel Rail Fuel Pressure Sensor Replacement

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

### Repair Verification

Ignition ON, observe the scan tool DPF soot mass parameter. The parameter should be less than 24 grams.

⇒ | If greater than the specified range, perform a DPF service regeneration. Refer to Exhaust Particulate Filter Cleaning .