Fuel Temperature Sensor, Checking

Diagnostic Procedures

Fuel Temperature Sensor, Checking

Observe all safety precautions: --> [ Safety Precautions ]

View clean working conditions: --> [ Clean Working Conditions ]

Prior to repair work, perform a preliminary check to verify the condition. Refer to --> [ Preliminary Check ] Preliminary Check.

Use only gold-plated terminals when servicing any component with gold-plated electrical harness connector terminals.

For wiring diagrams, component locations, and connector views, Refer to the applicable wiring diagram.

Special tools, testers and auxiliary items required

• Multimeter

• Wiring diagram

Test requirements

• The engine control module fuses OK

• Battery voltage at least 12.5 volts

• All electrical consumers switched off

• Vehicles with automatic transmission, shift selector lever in park or neutral

• A/C switched off

• Ground connections between engine/transmission/chassis OK

Test procedure

- Disconnect the Fuel Temperature Sensor (G81) electrical harness connector.

Checking internal resistance

- Using a multimeter, measure the resistance between the terminals of the Fuel Temperature Sensor (G81).

Use the chart below to estimate the specified values:





If the sensor value was not within the specified range:

- Replace the Fuel Temperature Sensor (G81).

Checking the voltage

- Disconnect the Fuel Temperature Sensor (G81) connector.

- Turn the ignition switch ON.

- Using a multimeter, measure the voltage between the Fuel Temperature Sensor (G81) terminal 2 and ground.

Specified value: near 5.0 V

If the specification was obtained:

- Using a multimeter, measure the voltage between the Fuel Temperature Sensor (G81) terminals 2 and 1.

Specified value: near 5.0 V

If the voltages above were Not obtained:

Checking the wiring

- Remove the Engine Control Module (ECM) (J623).





- Using a multimeter, measure the resistance of circuits between the Fuel Temperature Sensor (G81) and the Engine Control Module (ECM) (J623) electrical harness connectors. Refer to the applicable wiring diagram.

Specified value: 1.5 ohms Max.

If the specification was not obtained:

- Check the wires for high resistance, a short circuit to each other, a short to battery voltage, and a short to ground.

- Check the electrical harness connector for damage, corrosion, loose or broken terminals.

- Repair as necessary.

If no malfunction is detected in the sensor or wiring:

- Replace the Engine Control Module (ECM) (J623).

Final procedures

After repair work, the following work steps must be performed in the following sequence:

1. Check the DTC memory. Refer to --> [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Modes 01 - 09.

2. If necessary, erase the DTC memory. Refer to --> [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09.

3. If the DTC memory was erased, generate readiness code. Refer to --> [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.