P0183

CIRCUIT DESCRIPTION
The fuel temperature sensor is a thermistor that controls the signal voltage to the powertrain control module (PCM). When the fuel is cold, the sensor resistance is high, therefore the PCM will see 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 engine has been operating for at least 8 minutes.

CONDITIONS FOR SETTING THE DTC
^ The fuel temperature is less than or equal to 18°C (64°F).
^ The conditions are 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 fuel temperature in degrees Celsius.

A failure to detect an increase in fuel temperature could be the result of a faulty connection or an open in the signal circuit.

An intermittent may be caused by the following conditions:
^ Faulty connections
^ Rubbed-through wire insulation
^ A broken wire inside the insulation

TEST DESCRIPTION

Steps 1-11:

Steps 12-15:

The numbers below refer to the step numbers on the diagnostic table.
2. This step determines if DTC P0183 is a hard failure or an intermittent condition.
3. This test simulates a DTC P0182. If the PCM recognizes the low signal voltage, or a high temperature, the PCM and wiring are OK.
4. This test will determine if the signal circuit is open. There should be 5 volts at the sensor connector if measured with a DMM. This will determine if there is a wiring condition or a malfunctioning PCM.
9. This step determines if there is a short to voltage on the signal circuit. A short to voltage increases current flow through the sensor which overwhelms the sensor. This does not allow the sensor to pull down the circuit to the correct voltage and thus display the correct temperature.
10. After repairing the short to voltage, check the sensor for proper operation.