Service manual

G420F(FE) Service Manual Chapter 5. Engine Management System (EMS) 194
IAT (Intake Air Temperature)
Sensor
The intake air temperature sensor (IAT Sensor),
built in to the MAT sensor, is a resistor-based
sensor detect the intake air temperature. According
to the intake air temperature information frim the
sensor, the ECM will control the necessary amount
of fuel injection.
Ciruit Diagram
MAP & IAT
sensor
3214
Sensor
power
B24
IAT
signal
B12
Sensor
ground
B1
MAP
signal
B18
E C M
IAT
MAP
Sensor Inspection
1. Using a multimeter, measure the IAT sensor
resistance between terminals 3 and 4.
Temperature
℃ (°F)
Resistance(kΩ)
0 (32) 4.5 ~ 7.5
20 (68) 2.0 ~ 3.0
40 (104) 0.7 ~ 1.6
IG.SW.ON
80 (176) 0.2 ~ 0.4
2. If the resistance deviates from the standard value,
replace the intake air temperature sensor
assembly.