P1111

CIRCUIT DESCRIPTION
The Intake Air Temperature (IAT) sensor is a thermistor that measures the temperature of the air that is 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, indicating a low temperature, this Diagnostic Trouble Code (DTC) will set.

CONDITIONS FOR RUNNING THE DTC
^ DTCs P0101, P0102, P0103, P0117, P0118, P0125, P0502, P0503, P1114, and P1115 are not set.
^ The engine has been running for at least 5 seconds.
^ The Engine Coolant Temperature (ECT) is more than 60°C (140°F).
^ The Mass Air Flow (MAF) is less than 12 g/s.
^ The vehicle speed is less than 80 km/h (48 mph).

CONDITIONS FOR SETTING THE DTC
^ The IAT sensor signal voltage is more than 4.8 volts at approximately -24°C (-12°F).
^ The condition exists for less than 1 second.

ACTION TAKEN WHEN THE DTC SETS
^ The control module stores the DTC information into memory when the diagnostic runs and fails.
^ The Malfunction Indicator Lamp (MIL) will not illuminate.
^ The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
^ The driver information center, if equipped, may display a message.

CONDITIONS FOR CLEARING THE DTC
^ A current DTC "Last Test Failed" clears when the diagnostic runs and passes.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
^ Use a scan tool in order to clear the DTC.

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

TEST

Steps 1-6: