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 low reference 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 low fuel temperature signal voltage, a high temperature indication, this DTC will set.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0182 Fuel Temperature Sensor Circuit Low Voltage
Conditions for Running the DTC
| • | DTC P0116, P0117, P0118, P0128 are not set. |
| • | The engine is running. |
| • | The engine coolant temperature is less than 60°C (140°F). |
| • | The ignition voltage is more than 7 volts. |
| • | DTC P0182 runs continuously within the enabling conditions. |
Conditions for Setting the DTC
The fuel temperature sensor is more than 129.75°C (265.55°F) for 2 seconds.
OR
The fuel temperature sensor voltage is less than 0.24 volts 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
| • | After starting a cold engine, the fuel temperature should be within a few degrees of the intake air temperature (IAT) sensor. |
| • | Use the Temperature vs. Resistance table in order to test the fuel temperature sensor at various temperature levels in order to evaluate the possibility of a skewed sensor. A skewed sensor could result in poor driveability concerns. |
| • | If the condition is suspected of being an intermittent, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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If DTC P0182 can only be repeated by duplicating the Failure Records, refer to Temperature vs Resistance. The table may be used to test the fuel temperature sensor at various temperatures in order 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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When testing fuel temperature sensor signal circuit for a short to ground, you may need to inspect for continuity between all other engine control module circuits.
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 more than the specified value? | 130°C (266°F) | Go to Step 4 | Go to Step 3 |
Did the DTC fail this ignition? | -- | Go to Step 4 | Go to Diagnostic Aids | |
4 |
Is the fuel temperature sensor parameter less than the specified value? | -30°C (-86°F) | Go to Step 6 | Go to Step 5 |
Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 7 | |
6 | Replace the fuel temperature sensor. Refer to Fuel Temperature Sensor Replacement . Did you complete the replacement? | -- | Go to Step 8 | -- |
7 | 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 8 | -- |
8 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 9 |
9 | 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 |
