P0110

CIRCUIT DESCRIPTION

The Intake Air Temperature (IAT) sensor contains a semiconductor device which changes the resistance based on the temperature (a thermistor). The IAT sensor is located in the air intake passage of the engine air induction system. The IAT sensor has a signal circuit and a ground circuit. The ECM applies a voltage (about 5.0 volts) on the signal circuit to the sensor. The ECM monitors any changes in this voltage caused by changes in the resistance of the sensor in order to determine the intake air temperature.

When the intake air is cold, the sensor (thermistor) resistance is high,, and the ECM's signal voltage is only pulled down a small amount through the sensor to ground. Therefore, the ECM will sense a high signal voltage (low temperature). When the intake air is warm, the sensor resistance is low, and the signal voltage is pulled down a greater amount. This causes the ECM to sense a low signal voltage (high temperature).

When the ECM senses a signal voltage outside of the normal operating range of the sensor, this DTC will set.

CONDITIONS FOR RUNNING THE DTC

The engine must be running for at least 3 minutes


CONDITIONS FOR SETTING THE DTC

The IAT signal voltage indicates an intake air temperature that is greater than 139°C (282°F)

OR

^ The IAT signal voltage indicates an intake air temperature that is less than -43°C (-45°F).

^ The above condition is met for at least 10 seconds.

ACTION TAKEN WHEN THE DTC SETS

The ECM illuminates the Malfunction Indicator Lamp (MIL) and records the operating conditions in the Freeze Frame on the second consecutive drive trip that the diagnostic runs and fails.


CONDITIONS FOR CLEARING THE MIL/DTC

^ The ECM turns off the MIL after three consecutive drive trips that the diagnostic runs and does not fail.

^ A History DTC clears after forty consecutive warm-up cycles if no failures report by this diagnostic or any other emission related diagnostic.

^ The ECM battery voltage is interrupted.

^ The scan tool clears the MIL/DTC.

TEST DESCRIPTION

The number(s) below refer to the step numbers on the diagnostic table.

2. Determine if the circuit is currently malfunctioning.

3. Determine if the circuit is currently malfunctioning.

5. Using the Freeze Frame data may aid in locating an intermittent condition. If the DTC cannot be duplicated, review the information in the Freeze Frame. Try to operate the vehicle within the same freeze frame conditions (the RPM, the MAF, the vehicle speed, the temperature etc.) that were noted. This process may help to recreate the malfunction.