P0110

Circuit Description
The Intake Air Temperature (IAT) sensor contains a device which changes the resistance based on the temperature (a thermistor). The IAT sensor is located in the Mass Air Flow (MAF) sensor. 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. Therefore, the ECM will sense a high signal voltage (low temperature). When the intake air is warm, the sensor resistance is low. 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 more than 139°C (282°F).
OR
^ The IAT signal voltage indicates an Intake Air Temperature that is at -40°C (-40°F).
^ The above condition is met for at least 10 seconds in idle.

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 passes.
^ A History DTC clears after forty consecutive warm-up cycles in which no failures are reported 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 numbers below refer to the step numbers on the diagnostic table.
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.
17. The IAT sensor and the MAF sensor are replaced as an assembly. The IAT sensor is not to be serviced separately.
19. Perform the Idle Learn Procedure when replacing the ECM or throttle body.