GM Service Manual Online
For 1990-2009 cars only

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 P0182: Fuel Temperature Sensor Circuit Low Voltage

DTC P0183: Fuel Temperature Sensor Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

Fuel Temperature Signal

P0182

P0183²

P0183

P0183

--

Low Reference

--

²

P0183

¹

--

¹ Opens fuse in 12-volt circuit

² Temperature is skewed and may not have any codes

Typical Scan Tool Data

Fuel Temperature Sensor

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Operating Conditions: The Ignition ON, with the Engine OFF

Parameter Normal Range: -30 to +120°C (-22 to +248°F)

Fuel Temperature Signal

120°C (248°F)

Varies¹

-40°C (-40°F)

-40°C (-40°F)

¹ Skewed sensor

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 bias voltage cold and decreases as the sensor warms. The control module monitors the fuel temperature sensor signal circuit in order to calculate the temperature of the fuel entering the engine.

Conditions for Running the DTC

P0182

    • The ignition is ON.
    • DTC P0182 runs continuously within the enabling conditions.

P0183

    • The ignition is ON.
    • DTC P0183 runs continuously within the above enabling conditions.

Conditions for Setting the DTC

P0182

The fuel temperature sensor is more than 120°C (248°F) for 2 seconds.

P0183

The fuel temperature sensor is less than -30°C (-22°F) for 2 seconds.

Action Taken When the DTC Sets

    • The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

Diagnostic Aids

    • A short to a separate 5-volt source may set a DTC P0183.
    • A skewed sensor could result in poor driveability concerns.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Engine Controls Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs
    •  Temperature Versus Resistance

Circuit/System Verification

Important: If you cannot duplicate the condition, 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.

  1. Turn ON the ignition and observe the Fuel Temperature Sensor parameter with a scan tool. The fuel temperature parameter should be within the operating range.
  2. Engine running, observe the DTC information with a scan tool. DTCs P0182 or P0183 should not set.
  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

P0182

  1. Turn OFF the ignition for 30 seconds or until the ECM powers down.
  2. Disconnect the fuel temperature sensor .
  3. Turn ON the ignition, with the engine OFF and observe the fuel temperature sensor parameter with a scan tool. Fuel temperature should go to -40°C (-40°F).
  4. If the fuel temperature is warmer than -40°C(-40°F) , test the signal circuit for a short to ground, a short to any low reference circuits. If the circuits test normal, replace the control module.
  5. If all circuits test normal, replace the fuel temperature sensor.

P0183

  1. Turn ON the ignition, with the engine OFF and observe the fuel temperature sensor parameter with a scan tool.
  2. If the fuel temperature is colder than -30°C (-22°F), test the low reference circuit for an open. If the circuits test normal, replace the control module.
  3. Disconnect the fuel temperature sensor connector.
  4. Important: If a short to voltage is found, the fuel temperature sensor will also need to be replacement .

  5. Using a DMM, measure the voltage between the fuel temperature signal circuit and a ground.
  6. If the voltage measures more than 5.2 volts, test the signal circuit for a short to voltage. If the circuits test normal, replace the control module.
  7. Connect a 3A fused jumper between the signal circuit of the fuel temperature sensor and the low reference circuit.
  8. Observe the fuel temperature sensor parameter with a scan tool.
  9. If temperature is colder than 120°C (248°F), test the signal circuit for an open, high resistance or a faulty ECM.
  10. With the ignition still turned ON , connect a DMM between the signal circuit and a ground.
  11. With the DMM set to the mA scale, measure the current.
  12. If the current measures more than 15 mA , test the signal circuit for a short to a 5-volt reference circuit . If the circuits test normal, replace the control module.
  13. If all circuits test normal, replace the fuel temperature sensor.

Component Testing

  1. Disconnect the fuel temperature sensor and measure the resistance of the sensor with a DMM.
  2. Record the values at varies engine temperatures and compare those results to the Temperature vs. Resistance Table (Fuel Temperature).
  3. If the sensor does not closely match through the temperature ranges, replace the fuel temperature sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Fuel Temperature Sensor Replacement
    •  Control Module References for ECM replacement, setup, and programming