The Manifold Absolute Pressure (MAP) and the Intake Air Temperature (IAT) sensor 2 are an integrated sensor. The IAT sensor is a variable resistor that measures the temperature of the air entering the engine intake manifold. The powertrain control module (PCM) supplies 5 volts to the IAT sensor 2 signal circuit and a ground for the IAT sensor 2 low reference circuit. When the sensor is cold the resistance is greater. This results in a greater voltage on the signal circuit that is interpreted by the PCM as a colder IAT. As the sensor becomes warmer the resistance decreases. This results in a lesser voltage on the IAT signal circuit that is interpreted by the PCM as a warmer IAT.
Removal & Installation
- Disconnect the MAP/IAT sensor harness connector.
- Remove the IAT sensor bolt.
- While twisting the IAT sensor , pull the sensor from the engine.
- Installation is the reverse of removal.
- Turn OFF the ignition.
- Remove the IAT sensor.
- Place the sensor on a work surface away from any heat source.
- Allow the sensor to reach the ambient air temperature for 30-60 minutes.
- Observe and record the ambient air temperature of the vehicle environment using an accurate thermometer.
- Measure the resistance of the IAT sensor 2 and record the value.
Compare the resistance measurement of the IAT sensor to the ambient air temperature on the Temperature vs. Resistance chart illustration. If not within specification, replace the sensor.