DTC P0112: Intake Air Temperature Circuit Low Input; DTC P0113: Intake Air Temperature Circuit High Input: Description
- The intake air temperature sensor, mounted on the mass air flow meter, monitors the intake air temperature. The intake air temperature sensor has a built-in thermistor with a resistance that varies according to the temperature of the intake air. When the intake air temperature is low, the resistance of the thermistor increases. When the temperature is high, the resistance drops. These variations in resistance are transmitted to the ECM as voltage changes (see Fig 1).
- The intake air temperature sensor is powered by a 5 V supply from the THA terminal of the ECM, via resistor R.
- Resistor R and the intake air temperature sensor are connected in series. When the resistance value of the intake air temperature sensor changes, according to changes in the intake air temperature, 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 P0112 and P0113 are stored, the ECM enters fail-safe mode. During fail-safe mode, the intake air temperature 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 Condition | Trouble Area |
|---|---|---|
| P0112 | Short in intake air temperature sensor circuit for 0.5 seconds (1 trip detection logic) |
|
| P0113 | Open in intake air temperature sensor circuit for 0.5 seconds (1 trip detection logic) |
|
HINT:
When any of these DTCs are output, check the intake air temperature using the Techstream. Enter the following menus: Powertrain / Engine and ECT / Data List / Intake Air.
| Temperature Displayed | Malfunction |
|---|---|
| -40°C (-40°F) | Open circuit |
| Higher than 128°C (262°F) | Short circuit |