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).

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.