GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The fuel temperature sensor is a thermistor which controls the signal voltage to the powertrain control module (PCM). When the fuel is cold, the sensor resistance is high, and the PCM will see a high signal voltage. As the fuel warms, the sensor resistance becomes less and the voltage drops. The fuel temperature sensor is integrated with the optical sensor.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

    • The fuel temperature is more than 102°C (215°F).
    • The conditions were met for 2 seconds.

Action Taken When the DTC Sets

    • The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the 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 scan tool reads the fuel temperature in degrees Celsius.

An intermittent may be caused by the following conditions:

    • Faulty connections
    • Rubbed-through wire insulation
    • A broken wire inside the insulation

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step determines if DTC P0182 is a hard failure or an intermittent condition.

  2. This test will determine if signal circuit is shorted to ground.

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

1

Did you perform the Diagnostic System Check-Engine Controls?

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Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

  1. Connect the scan tool.
  2. Start the engine.
  3. Monitor the Fuel Temp display on the scan tool.

Is the Fuel Temp more than the specified value?

102°C (215°F)

Go to Step 3

Go to Step 5

3

  1. Turn OFF the engine.
  2. Turn ON the ignition.
  3. Disconnect the optical/fuel temperature sensor connector.

Is the Fuel Temp less than or equal to the specified value?

17°C (63°F)

Go to Step 7

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the PCM connector with the fuel temperature signal circuit.
  3. Use the DMM in order to measure the resistance across the fuel temperature signal circuit and a known good ground at the sensor harness connector.

Does the DMM indicate OL?

--

Go to Step 8

Go to Step 6

5

The DTC is intermittent.

Are any additional DTCs stored?

--

Go to Diagnostic Trouble Code (DTC) List

Go to Diagnostic Aids

6

Repair the short to ground in the fuel temperature signal circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 9

--

7

Important: If the fuel injection pump is malfunctioning, the new injection pump must be timed. Refer to Fuel Injection Pump Timing Adjustment .

Replace the fuel injection pump. Refer to Fuel Injection Pump Replacement .

Did you complete the replacement?

--

Go to Step 9

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8

Replace the PCM. Refer to Powertrain Control Module Replacement .

Did you complete the replacement?

--

Go to Step 9

--

9

  1. Use a scan tool in order to clear the DTCs.
  2. Start the engine.
  3. Allow the engine to idle until the normal operating temperature is reached.
  4. Select DTC and the Specific DTC function.
  5. Enter the DTC number that was set.
  6. Operate the vehicle within the Conditions for Setting this DTC until the scan tool indicates the diagnostic ran.

Does the scan tool indicate the diagnostic passed?

--

Go to Step 10

Go to Step 2

10

Does the scan tool display any additional undiagnosed DTCs?

--

Go to Diagnostic Trouble Code (DTC) List

System OK