Air Temperature Sensor ( Ambient / Intake ): Testing and Inspection
IAT Sensor Resistance Inspection1. Disconnect the MAF sensor connector.
Specification:
2. Measure the resistance between MAF sensor terminals D and E using an ohmmeter.
- 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, carry out the "Circuit Open/Short Inspection".
IAT sensor signal characteristic (reference)
Circuit Open/Short Inspection
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 N.m {80 - 110 kgf.cm, 69.5 - 95.4 in.lbf}
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)
- GND 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 GND)
5. Reconnect the sensor connector.