P0187

DTC P0182, P0183, P0187, or P0188

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptors
DTC P0182
- Fuel Temperature Sensor 1 Circuit Low

DTC P0183
- Fuel Temperature Sensor 1 Circuit High

DTC P0187
- Fuel Temperature Sensor 2 Circuit Low

DTC P0188
- Fuel Temperature Sensor 2 Circuit High

Diagnostic Fault Information





Circuit/System Description

The fuel temperature sensor is a thermistor. The engine control module (ECM) supplies the fuel temperature sensor a bias voltage of 5 volts on the signal circuit and also provides a low reference circuit to the sensor. When the fuel temperature sensor is cold, the resistance is high. The fuel temperature sensor signal voltage remains near the 5 volt bias voltage cold and decreases as the sensor warms. The ECM monitors the fuel temperature sensor signal circuit in order to calculate the temperature of the fuel entering and leaving the engine fuel rail.

Conditions for Running the DTC

P0182 or P0187
* Engine speed is greater than 600 RPM.
* Engine has been running for greater than 10 seconds.
* DTCs P0182 and P0187 run continuously within the enabling conditions.

P0183 or P0188
* Engine speed is greater than 600 RPM.
* Engine has been running for greater than 10 seconds.
* DTCs P0183 and P0188 run continuously within the above enabling conditions.

Conditions for Setting the DTC

P0182 or P0187

The fuel temperature sensor is more than 150°C (302°F) for 5 seconds.

P0183 or P0188

The fuel temperature sensor is less than -50°C (-58°F) for 5 seconds.

Action Taken When the DTC Sets

DTCs P0182, P0183, P0187 and P0188 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0182, P0183, P0187 and P0188 are Type B DTCs.

Reference Information
Schematic Reference

Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

Fuel System Description (Fuel System Description)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
* Temperature Versus Resistance (IAT Sensor 2) (Temperature Versus Resistance (IAT Sensor 2)) Temperature Versus Resistance (EGT Sensors) (Temperature Versus Resistance (EGT Sensors)) Temperature Versus Resistance (ECT Sensors) (Temperature Versus Resistance (ECT Sensors)) Temperature Versus Resistance (EGR Temperature Sensors) (Temperature Versus Resistance (EGR Temperature Sensors)) Temperature Versus Resistance (EGT Sensors 3 and 4) (Temperature Versus Resistance (EGT Sensors 3 and 4)) Temperature Versus Resistance (Fuel Temperature Sensor) (Temperature Versus Resistance (Fuel Temperature Sensor))

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

1. Ignition ON, observe the Fuel Temperature Sensor and Fuel Rail Temperature Sensor parameters with a scan tool. Both fuel temperature parameters should be within the operating range of -50 to 150°C (-50 to 302°F).
2. 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

DTC P0182 or P0183
1. Ignition OFF, disconnect the harness connector at the B48 fuel temperature sensor.
2. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 1 and ground.

• If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
• If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.

3. Verify the scan tool Fuel Temperature Sensor parameter is less than -40°C (-40°F).

• If greater than the specified value, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the K20 engine control module.

4. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the 5 V reference circuit terminal 1. Verify the scan tool Fuel Temperature Sensor parameter is greater than 120°C (248°F).

• If less than the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.

5. If all circuits test normal, test or replace the B48 fuel temperature sensor.

DTC P0187 or P0188
1. Ignition OFF, disconnect the harness connector at the B132 fuel rail temperature sensor.
2. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 1 and ground.

• If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
• If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.

3. Verify the scan tool Fuel Rail Temperature Sensor parameter is less than -40°C (-40°F).

• If greater than the specified value, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the K20 engine control module.

4. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the 5 V reference circuit terminal 1. Verify the scan tool Fuel Rail Temperature Sensor parameter is greater than 120°C (248°F).

• If less than the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.

5. If all circuits test normal, test or replace the B132 fuel rail temperature sensor.

Component Testing

Measure and record the resistance of the fuel temperature sensor at various ambient temperatures and compare those measurements to the Temperature vs. Resistance table. Refer to Temperature Versus Resistance (IAT Sensor 2) (Temperature Versus Resistance (IAT Sensor 2)) Temperature Versus Resistance (EGT Sensors) (Temperature Versus Resistance (EGT Sensors)) Temperature Versus Resistance (ECT Sensors) (Temperature Versus Resistance (ECT Sensors)) Temperature Versus Resistance (EGR Temperature Sensors) (Temperature Versus Resistance (EGR Temperature Sensors)) Temperature Versus Resistance (EGT Sensors 3 and 4) (Temperature Versus Resistance (EGT Sensors 3 and 4)) Temperature Versus Resistance (Fuel Temperature Sensor) (Temperature Versus Resistance (Fuel Temperature Sensor)).

Repair Instructions

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

* Fuel Temperature Sensor Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for ECM replacement, setup, and programming