Circuit Description
The fuel temperature sensor is a thermistor. The engine control module (ECM) supplies the fuel temperature sensor a reference voltage of 5 volts on the signal circuit, and also provides a ground circuit to the sensor. When the fuel temperature sensor is cold, the resistance is high. The fuel temperature sensor signal voltage remains near the supplied voltage cold, and decreases the signal voltage 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. If the ECM detects an excessively high fuel temperature sensor voltage, a low temperature indication, this DTC will set.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0183 Fuel Temperature Sensor High Voltage
Conditions for Running the DTC
The vehicle has been driven for more than 8 minutes.
Conditions for Setting the DTC
| • | The fuel temperature sensor is less than -30°C (-22°F) for 2 seconds. |
| • | DTC P0183 runs continuously within the above enabling conditions. |
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 DTC may set. If this is the condition, 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 to test the fuel temperature sensor at various temperature levels, and 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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This step 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 - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Is the Fuel Temperature Sensor parameter 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 | |
Is the voltage more than the specified value? | 5.2 V | Go to Step 5 | Go to Step 6 | |
5 |
Important: If a short to battery voltage occurs, the fuel temperature sensor may be damaged. Test the fuel temperature sensor signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 12 |
6 |
Is the fuel temperature sensor parameter more than the specified value? | 138°C (280°F) | Go to Step 10 | Go to Step 7 |
7 |
Is the fuel temperature sensor parameter more than the specified value? | 138°C (280°F) | Go to Step 9 | Go to Step 8 |
8 | Test the fuel temperature sensor signal circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 12 |
9 | Test the low reference circuit of the fuel temperature sensor for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 12 |
10 | 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 11 |
11 | Test for an intermittent and for a poor connection at the fuel temperature sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 13 |
12 | Test for an intermittent and for a poor connection at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 14 |
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 Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 15 | -- |
15 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 16 |
16 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK |
