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.
If measured temperature is lower than the minimum threshold value during 1sec, PCM sets DTC P0113.
(In this case, the input signal voltage is the maximum threshold vaue.)
Item
Detecting Condition
Possible Cause
DTC Strategy
Signal check, high
Poor connection
Open or short to power in signal circuit
Open in ground circuit
IATS
Enable Conditions
ECT > 70C
Air mass < 32kg/h
Vehicle speed < 7mph
Threshold value
Intake air temperature sensor's voltage > 3.28V
Diagnosis Time
1 sec
MIL On Condition
2 Driving Cycles
Temp. (?)
Resistance (k?)
-40
40.93 ~ 48.35
20
2.31 ~ 2.57
-20
13.89 ~ 16.03
40
1.08 ~ 1.21
0
5.39 ~ 6.09
60
0.54 ~ 0.62
10
3.48 ~ 3.90
80
0.29 ~ 0.34