Air Temperature Sensor ( Ambient / Intake ): Testing and Inspection

NOTE: Perform the following test only when directed.

IAT Sensor Resistance Inspection

1. Disconnect the MAF sensor connector.
2. Measure the resistance between MAF sensor terminals D and E using an ohmmeter.




Specification

- If not as specified, replace the MAF sensor.

- If IAT sensor is okay, but PID value or PCM terminal 39 voltage are out of specification, inspect the following:
1. Remove the PCM.




2. Connect the SST (104 Pin Breakout Box) to the PCM as shown.
3. Tighten the connector attaching screw.

Tightening torque
7.9 - 10.7 Nm (80 - 110 kg.cm, 69.5 - 95.4 in.lb)

4. Inspect for an open or short circuit in the following wiring harnesses by probing the applicable sensor and SST (104 Pin Breakout Box) terminals with ohmmeter leads.
- If there is an open or short circuit, repair or replace wiring harnesses.
- If there is no open or short circuit, replace the MAF sensor.




Open circuit
- IAT signal circuit (MAF sensor connector terminal D and PCM connector terminal 39)
- Ground circuit (MAF sensor connector terminal E and PCM connector terminal 91 through common connector)

Short circuit
- IAT signal circuit (MAF sensor connector terminal D and PCM connector terminal 39 to Ground)

3. Reconnect the sensor connector.