Code P0112, IAT Sensor Circuit Low Input - "S" & "T" Series 4.3L (VIN W): Notes

Intake Air Temperature (IAT) sensor is a thermistor. Control module applies and monitors 5 volts to sensor. When air is cold, sensor resistance is high and control module will measure a high signal voltage. If air is warm, sensor resistance is low causing control module to measure low voltage.

With Code P0112 set, control module will substitute a default value for intake air temperature. Code P0112 does not illuminate 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 control module are okay.