Code P0112, IAT Sensor Circuit: Notes

The Intake Air Temperature (IAT) sensor is a thermistor. PCM applies and monitors 5 volts to sensor. When air is cold, sensor resistance is high and PCM will measure a high signal voltage. If air is warm, sensor resistance is low causing PCM to measure low voltage. With Code P0112 set, PCM will substitute a default value for intake air temperature. Code P0112 does not illuminate the Malfunction Indicator Light (MIL).

1. An open sensor, wire or connection will cause Code P0112 to set. An open circuit would cause Tech-1 to display about -40°F (-40°C). This test determines if wiring and PCM are okay.