Ignition "ON"
Blow air with changing temperature to the in car sensor air inlet. Measure sensor resistance between 2 and 4 terminals
Temperature [℃(℉)]  | Resistance between terminals 2and 4 (㏀)  | 
-20(-4)  | 290.21  | 
-10(14)  | 165.6  | 
0 (32)  | 97.83  | 
10(50)  | 59.67  | 
20(68)  | 37.48  | 
30(86)  | 24.17  | 
40(104)  | 115.98  | 
50(122)  | 10.81  | 
In car sensor is negative type thermistor that resistance will rise with lower temperature, and reduce with higher temperature.