Circuit Description

Intake Air Temperature (IAT) sensor is a thermistor, which varies resistance based on temperature. As temperature of sensor increases, resistance decreases. High temperature will result in a low signal voltage. DTC will set when PCM senses IAT sensor voltage is excessively low (shorted to ground).

Conditions required to set DTC are:

• Vehicle driven at 30 MPH or more.
• Engine running more than 2 minutes.
• IAT voltage is less than .10 volts for 12.5 seconds over a 25-second period.
• Listed conditions are present for at least 2 seconds.