Circuit Description
The fuel temperature sensor is a thermistor. The engine controlmodule (ECM) supplies the fuel temperature sensor a reference voltage of 5 voltson the signal circuit and also provides a ground circuit to the sensor. When thefuel temperature sensor is cold, the resistance is high. The fuel temperature sensorsignal voltage remains near the supplied voltage cold and decreases the signalvoltage as the sensor warms. The control module monitors the fuel temperature sensorsignal circuit in order to calculate the temperature of the fuel entering the engine.If the ECM detects an excessively high fuel temperature sensor voltage, a low temperatureindication, this DTC will set.
Conditions for Running the DTC
The engine has been running for more than 4 minutes.
Conditions for Setting the DTC
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
| • | 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 Intermittent Conditions . |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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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.
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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.
Step | Action | Values | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views | ||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||
2 |
Does the fuel temperature sensor measure less than the specified value? | -30°C (-22°F) | Go to Step 4 | Go to Step 3 | ||||
Does the DTC reset? | -- | Go to Step 4 | Go to Diagnostic Aids | |||||
Does the fused jumper open? | -- | Go to Step 12 | Go to Step 5 | |||||
5 | Observe the fuel temperature sensor with the scan tool. Is the fuel temperature more than the specified value? | 138°C (280°F) | Go to Step 6 | Go to Step 7 | ||||
6 | Test the signal circuit of the fuel temperature sensor for a short to any other 5-volt reference circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 10 | ||||
7 |
Does the fuel temperature sensor measure more than the specified value? | 138°C (280°F) | Go to Step 9 | Go to Step 8 | ||||
8 |
Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 11 | ||||
9 |
Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 11 | ||||
10 |
Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 13 | ||||
11 |
Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 14 | ||||
12 | Repair the short to battery voltage on the fuel temperature signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 15 | -- | ||||
13 | Replace the fuel temperature sensor. Refer to Fuel Temperature Sensor Replacement . Did you complete the replacement? | -- | Go to Step 15 | -- | ||||
14 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | -- | Go to Step 15 | -- | ||||
15 |
Does the DTC run and pass? | -- | Go to Step 16 | Go to Step 2 | ||||
16 | With the scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK | |||||
