Air Temperature Sensor ( Ambient / Intake ): Testing and Inspection
INTAKE AIR TEMPERATURE (IAT) SENSOR INSPECTIONResistance Inspection
NOTE: Perform the following test only when directed.
1. Remove the IAT sensor.
Specification:
2. Measure the resistance of the IAT sensor terminals A and B using an ohmmeter.
- If not as specified, replace the IAT 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. Disconnect the PCM connector.
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 IAT sensor.
Open circuit
- IAT signal circuit (IAT sensor connector terminal A and PCM connector terminal 39)
- GND circuit (IAT sensor connector terminal B and PCM connector terminal 91)
Short circuit
- IAT signal circuit (IAT sensor connector terminal A and PCM connector terminal 39 to GND)
5. Install the IAT sensor.