The Intake Air Temperature Sensor (IATS) is installed into the Manifold Absolute Pressure Sensor (MAPS). 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 5V 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.
PCM sets DTC P0113 if the PCM 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 ?(-22?)
Threshold Value
IAT voltage > 4.93V
Diagnostic Time
10sec.
Mil On Condition
2 Drive Cycles
Temp.(?)
Resistance(?)
-10
14
8.5~9.7
20
68
2.3~2.5
0
32
5.4~6.1
30
86
1.6~1.7
10
50
3.5~3.9
80
176
Approx. 0.3