Intake Air Temperature Sensor, Checking

Intake Air Temperature Sensor, Checking

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

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

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

• The Charge Air Pressure Sensor and IAT Sensor are combined and must be replaced as a unit.

• Use only gold-plated terminals when servicing terminals in the electrical harness connector of the Charge Air Pressure Sensor/IAT sensor (G31/G42).

Special tools, testers and auxiliary items required

• Multimeter.

• Wiring diagram.

Test procedure

- Perform a preliminary check to verify the customers complaint. Refer to => [ Preliminary Check ] Preliminary Check

Start diagnosis

- Connect the scan tool.

- Engine must be at room temperature.

- Switch the ignition On.

- Using the scan tool, check the intake air temperature:






If the specified value was obtained:

- Fault is intermittent. Check for proper connection, damaged wiring or loose terminals.

If the specified value was Not obtained:

Checking internal resistance

- Disconnect the Charge Air Pressure Sensor/IAT sensor (G31/G42) electrical harness connector.

- Using a multimeter, check the Charge Air Pressure Sensor/IAT sensor (G31/G42) terminals 1 to 2 for resistance.

Use the chart below for the specified values:

Specified values:






If the specified value was Not obtained:

- Replace the Charge Air Pressure Sensor/IAT sensor (G31/G42) Refer to the Repair Information.

If the specified value was obtained:

- Turn the ignition switch ON

- Check the voltage from terminal 1 to terminal 2 of the IAT connector.

Specified value: Min. 4.40 V

If the specified value was Not obtained:

Checking wiring

- Remove the Engine Control Module (ECM) (J623). Refer to the Repair Information.

- Using a multimeter, check the Charge Air Pressure Sensor/IAT sensor (G31/G42) electrical harness connector to the Engine Control Module (ECM) (J623) electrical harness T94 connector for resistance. Refer to Wiring Diagrams for Pin locations.






Specified value: 1.5 ohms Max.

If the specification was not obtained:

- Check the wiring for a short circuit to each other, Battery positive, Ground or high resistance.

- If necessary, repair the faulty wiring connection.

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

If no malfunction is detected in the wiring and the voltage readings were Not correct:

- Replace the Engine Control Module (ECM) (J623). Refer to the service information for removal and installation procedures.

Final procedures

After the 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.