The Intake Air Temperature (IAT) sensor measures the temperature of engine intake air. The Intake Air Temperature (IAT) sensor is a thermistor (a variable resistor that changes along with outside air temperature) in series with a fixed resistor in the PCM. The PCM applies 5volts to the IAT sensor. The PCM monitors the voltage across the IAT sensor and converts it into a temperature reading. When the outside air temperature is cold the IAT sensor resistance is high, and when the outside air temperature is warm the IAT sensor resistance is low. Therefore, when the air temperature is cold the PCM will receive a high voltage input, and when the air temperature is warm the PCM will receive a low voltage input. The signal from IAT sensor is used for injection time correction (Cold post start correction), ignition angle correction(Air temperature correction) and idle speed correction(Air-density correction).
Checking output signals of IATS every 20 sec. under detecting condition, if an ouput signal is over 4.9V for more than 10 sec., PCM sets P0113. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
Item | Detecting Condition | Possible cause |
DTC Strategy | ● This code detects a continuous short to high in either the signal circuit or the sensor | ● Poor connection ● Open or short to battery in harness ● Open in ground harness ● IATS ● PCM |
Enable Conditions | ● No vehicle speed sensor fault ● No ECTS fault ● No MAFS fault ● Vehicle speed ＜ 25kph (9.3mph) ● Intake airflow ＜ 15g/s ● ECT ＞ 50℃(122℉) and Engine running time ＞ 120s (or time from IG "OFF" to IG "ON" ＞ 360 min and ECT ＞ -10℃(14℉)) ● Engine running state | |
Threshold Value | ● Intake air temperature sensor’s voltage >4.9V | |
Diagnosis Time | ● Continuous (More than 10 seconds failure for every 20 seconds test) | |
MIL On Condition | ● 2 Driving Cycles |
Temp. (°C/°F) | Resistance (kΩ) | Temp. (°C/°F) | Resistance (kΩ) |
-40(-40) | 95.95 ~ 105.78 | 20(68) | 3.42 ~ 3.61 |
-20(-4) | 27.4 ~ 29.77 | 40(104) | 1.43 ~ 1.5 |
0(32) | 9.08 ~ 9.72 | 60(140) | 0.66 ~ 0.69 |
10(50) | 5.49 ~ 5.83 | 80(176) | 0.33 ~ 0.34 |
