Intake Air Temperature Sensor
DESCRIPTIONThis pin provides an input signal to the Powertrain Control Module (PCM). The intake manifold air temperature sensor is a variable, thermistor type.
OPERATION
The intake manifold air temperature sensor reacts to temperature changes. At cold air temperatures, its resistance is high. As temperatures increase, its resistance will decrease. The air temperature sensor element extends into the intake manifold air stream.
As the temperature of the air-fuel stream in the manifold varies, the sensor resistance will change. This will result in a different input voltage to the PCM.
PURPOSE
It provides an input voltage to the PCM indicating intake manifold air temperature. The input from this sensor is used by the PCM to determine if and how long to activate the intake manifold air heater relays. When the relays are activated, current will flow through the relays to the intake manifold air heater.
Also refer to Intake Manifold Heater Relays-PCM Pin #15-PCM Output for additional information. Intake Manifold Air Heater Relays