Neon L4-2.0L VIN C (1997)
Intake Air Temperature Sensor: Description and Operation
MAP/IAT Sensor
PURPOSE
The intake air temperature sensor measures the temperature of the air as it enters the engine. The sensor supplies one of the inputs the PCM uses to
determine injector pulse-width.
CONSTRUCTION
The MAP/Intake Air Temperature (IAT) sensor, located on the intake manifold, combines the MAP and Intake Air Temperature (IAT) functions
into one sensor.
CIRCUIT OPERATION
The intake air temperature sensor provides an input to the Powertrain Control Module (PCM) on circuit K21. Circuit K21 connects to cavity 37 of
the PCM connector.
From circuit K21 the intake air temperature sensor draws voltage from the PCM. The sensor is a variable resistor As intake air temperature
changes the resistance in the sensor changes causing a change in current draw.
The PCM provides ground for the intake air temperature sensor signal (circuit K21) through circuit K4. Circuit K4 connects to cavity 43 of the
PCM connector.
