P1111

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 high IAT signal voltage (low temperature indicated), DTC P1111 will set.

CONDITIONS FOR RUNNING THE DTC
^ No ECT sensor, or VSS DTCs are set.
^ Engine has been running for at least 5 seconds.
^ Engine coolant temperature is greater than 0°C (32°F).
^ Vehicle speed is less than 80 km/h (50 mph).

CONDITIONS FOR SETTING THE DTC
^ The IAT sensor signal voltage is greater than 4.8 volts (approximately -24°C (-12°F)).
^ The condition exists for approximately 5 seconds.

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