P0183

CIRCUIT DESCRIPTION
The fuel temperature sensor is a thermistor. The Engine Control Module (ECM) supplies the FT sensor a reference voltage of 5 volts on the signal circuit and also provides a ground circuit to the sensor. When the FT sensor is cold, the resistance is high. The FT sensor signal voltage remains near the supplied voltage cold and decreases the signal voltage as the sensor warms. The control module monitors the FT sensor signal circuit in order to calculate the temperature of the fuel entering the engine. If the ECM detects an excessively high FT voltage (a low temperature indication) this DTC will set.

CONDITIONS FOR RUNNING THE DTC
The engine has been running for more than 8 minutes.

CONDITIONS FOR SETTING THE DTC
The fuel temperature sensor temperature 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) 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.
^ Use a scan tool in order to clear the MIL and the DTC.

DIAGNOSTIC AIDS
If a short to a separate 5-volt source occurs, this Diagnostic Trouble Code (DTC) may set. If this is the problem, a continuity test to all other ECM circuits will be necessary in order to diagnose the specific circuit.

After starting a cold engine, the fuel temperature sensor should be within a few degrees of the Intake Air Temperature (IAT) reading

Use the Temperature vs. Resistance Table in order to test the fuel temperature sensor at various temperature levels and in order to evaluate the possibility of a skewed sensor.

If the condition is suspected of being intermittent, refer to Testing for Intermittent and Poor Connections.

TEST DESCRIPTION

Steps 1-7:

Steps 8-13:

The numbers below refer to the step numbers on the diagnostic table.
3. If DTC P0183 can only be repeated by duplicating the Failure Records, refer to the Temperature vs Resistance table. The table may be used to test the fuel temperature sensor at various temperatures to evaluate the possibility of a shifted sensor that may be shorted above or below a certain temperature. If this is the case, replace the fuel temperature sensor. If the fuel temperature sensor appears to be OK, the malfunction is intermittent. Refer to Diagnostic Aids.
4. Tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.
10. The ECM in this vehicle uses an Electrically Erasable Programmable Read-only Memory (EEPROM). If the PCM is replaced, the new ECM must be programmed.