It is a negative type thermistor whose resistance is inversely proportional to temperature. Its output is used for sensor fail-safe, temperature regulation door lock, blower motor level control, mix mode control.
Air conditioner Control Module sets DTC B1237 if Ambient sensor has been detected below 0.1V for 100ms.
Item
Detecting Condition
Possible Cause
DTC Strategy
Voltage check
Short in signal circuit
Faulty Ambient Sensor
Faulty A/C control Module
Enable Conditions
IG KEY ON
Threshold value
Ambient sensor has been dtected 0.1V for 100ms.
Fail safe
Control with the value of 20?(68?)
? Resistance value of incar temp sensor as a function of temperature.
Temperature(?/?)
Resistance(?)
-20/-4
284.5 ± 3%
10/50
59.6 ± 3%
-10/14
164.2 ± 3%
30/86
24.18 ± 3%
0/32
97.5 ± 3%
50/122
10.83 ± 3%