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 ECM is supplied to the IATS via a resistor in the ECM. That is, the resistor in the ECM 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 ECM corrects basic fuel injection duration and ignition timing.
ECM sets DTC P0113 if the ECM detects signal voltage higher than the possible range of a properly operating IATS.
Item
Detecting Condition
Possible Cause
DTC Strategy
? Voltage range check
? Short to battery in signal harness
? Open in signal or ground circuit
? Poor connection or damaged harness
? Faulty IAT sensor
Enable Conditions
? Battery voltage >6V
? Time after start > 105 sec., if Air temperature at Start > -30 °C(-22°F)
Threshold Value
? IAT voltage > 4.93V
Diagnostic Time
? 10sec.
Temp.(°C)
Temp.(°F)
Resistance(k?)
-10
14
8.7~9.7
20
68
2.4~2.5
0
32
5.5~6.1
30
86
1.6~1.7
10
50
3.6~3.9
80
176
Approx. 0.3