For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptor

DTC P0182 00: Fuel Temperature Sensor Circuit Low Voltage
DTC P0183 00: Fuel Temperature Sensor Circuit High Voltage

#### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
Signal | P0182 | P0183 | P0183 | --
Low reference | -- | P0183 | -- | --

### Typical Scan Tool Data

#### Fuel Temperature Sensor

Circuit | Short to Ground | Open | Short to Voltage
--- | --- | --- | ---
Operating Conditions: Ignition ON Parameter Normal Range: 0.12-4.9 V
Signal | 0.0 V | 5.0 V | 5.0 V
Low Reference | 5.0 V | 5.0 V | --

### Circuit/System Description

The fuel temperature sensor is integrated within the fuel filter assembly. The fuel temperature sensor is a variable resistor that measures the temperature of the fuel. The engine control module (ECM) supplies 5 V to the signal circuit and supplies a ground to the low reference circuit. The following table illustrates the difference between temperature, resistance, and voltage:

Fuel Temperature Sensor | Resistance | Signal Voltage
--- | --- | ---
Cold | High | High
Warm | Low | Low

### Conditions for Running the DTC

• | The ignition is ON or the engine is running.

• | The DTCs run continuously once the above condition is met

### Conditions for Setting the DTC

#### P0182

The ECM detects that the fuel temperature sensor voltage is less than 0.127 V for 0.5 s.

#### P0183

The ECM detects that the fuel temperature sensor voltage is greater than 4.9 V for 0.5 s.

### Action Taken When the DTC Sets

DTCs P0182, and P0183 are Type B DTCs.

### Conditions for Clearing the DTC

DTCs P0182, and P0183 are Type B DTCs.

### Diagnostic Aids

• | A short to a separate 5-volt source may set a DTC P0183.

• | A skewed sensor may result in poor driveability concerns.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Engine running, observe the DTC information with a scan tool. DTCs P0182, or P0183 should not set.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the B48 Fuel Temperature Sensor.
2. Test for less than 5 Ω between the low reference circuit terminal 1 (X1) and ground.

⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

3. Ignition ON, verify the scan tool Fuel Temperature Sensor parameter is at 5 V.

⇒ | If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

Note: If the fuse in the jumper wire opens, the signal circuit is shorted to a voltage and the sensor may be damaged.

4. Install a 1 A fused jumper wire between the signal circuit terminal 2 (X1) and ground. Verify the scan tool Fuel Temperature Sensor parameter is less than 0.3 V.

⇒ | If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

5. If all circuits test normal, replace the B48 Fuel Temperature Sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Link

• | Control Module References for ECM replacement, setup, and programming