The Intake Air Temperature Sensor (IATS) is installed into the Mass Air Flow Sensor (MAFS). The IATS uses a thermistor whose resistance changes with the temperature. The electrical resistance of the IATS decreases as the temperature increases, and increases as the temperature decreases. The 5 V power source in the PCM is supplied to the IATS via a resistor in the PCM. That is, the resistor in the PCM and the thermistor in the IATS are connected in series. When the resistance value of the thermistor in IATS changes according to the intake air temperature, the signal voltage also changes. Using this signal, the information of the intake air temperature, the PCM corrects basic fuel injection duration and ignition timing.
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 |
