DTC P0110 Intake Air Temperature Circuit; DTC P0112 Intake Air Temperature Circuit Low Input; DTC P0113 Intake Air Temperature Circuit High Input: Description
The Intake Air Temperature (IAT) sensor, built into the Mass Air Flow (MAF) meter, monitors the intake air temperature. The IAT sensor has a thermistor that varies its resistance depending on the intake air temperature. When the intake air temperature is low, the resistance in the thermistor increases. When the temperature is high, the resistance drops. The variations in resistance are reflected as voltage changes to the ECM terminal (see Fig 1).
The IAT sensor is connected to the ECM. The 5 V power source voltage in the ECM is applied to the IAT sensor from terminal THA via resistor R.
Resistor R and the IAT sensor are connected in series. When the resistance value of the IAT sensor changes, according to changes in the IAT, the voltage at terminal THA also varies. Based on this signal, the ECM increases the fuel injection volume when the engine is cold to improve driveability.
HINT:
When any of DTCs P0110, P0112 and P0113 are set, the ECM enters fail-safe mode. During fail-safe mode, the IAT is estimated to be 20°C (68°F) by the ECM. Fail-safe mode continues until a pass condition is detected.
| DTC No. | DTC Detection Conditions | Trouble Areas |
|---|---|---|
| P0110 | Open or short in IAT sensor circuit for 0.5 seconds (1 trip detection logic) |
|
| P0112 | Short in IAT sensor circuit for 0.5 seconds (1 trip detection logic) |
|
| P0113 | Open in IAT sensor circuit for 0.5 seconds (1 trip detection logic) |
|
HINT:
When any of these DTCs are set, check the Intake Air Temperature (IAT) by selecting the following menu items on the Techstream: Powertrain/Engine and ECT/All Data/Intake Air.
| Temperature Displayed | Malfunctions |
|---|---|
| -40°C (-40°F) | Open circuit |
| 140°C (284°F) | Short circuit |