P1112

Diagnostic Chart:

Schematic:

CIRCUIT DESCRIPTION
The Intake Air Temperature (IAT) sensor is a thermistor (a variable resistor) that measures the temperature of the air entering the engine. The Powertrain Control Module (PCM) supplies 5 volts to the IAT signal circuit through a pull-up resistor. When the intake air is cold, the PCM detects a high voltage on the IAT signal circuit. As the intake air warms, the PCM detects a lower voltage on the IAT signal circuit. If the PCM detects an intermittently low IAT signal voltage (high temperature indicated), DTC P1112 will set.

CONDITIONS FOR RUNNING THE DTC
^ No ECT sensor, or VSS DTCs are set.
^ Engine coolant temperature is less than 100°C (212°F).
^ Vehicle speed is greater than 15 km/h (9 mph).
^ Engine run time is greater than 10 seconds.

CONDITIONS FOR SETTING THE DTC
^ The IAT sensor signal voltage is less than 0.08 volts (approximately 133°C (271°F)).
^ The condition exists for less than 5 second.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM will illuminate the Malfunction Indicator Lamp (MIL) the first time the malfunction is detected.
^ The PCM will store conditions which were present when the DTC set as Freeze Frame and Fail Records data.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM will turn the MIL OFF during the third consecutive trip in which the diagnostic has been run and passed.
^ The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using the scan tool Clear DTC Information function.

DIAGNOSTIC AIDS
If the condition is intermittent, refer to Intermittent Conditions in Symptoms. Intermittent Conditions