The ambient temperature sensor located at the center stay of the condensor detects ambient air temperature. 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 and in-car humidity control.
Air conditioner Control Module sets DTC B1238 if Ambient sensor has been detected over 4.9V for 4 seconds.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Voltage check | 1. Poor Connection in harness 2. Open in signal circuit 3. Shrot to battery in signal circuit 4. Faulty Ambient Temperature sensor 5. Faulty air condtioner control Module |
Enable Conditions |
•
IG KEY ON | |
Threshold value |
•
Ambient Temperature sensor has been detected over 4.9V for 4 seconds. | |
Failsafe |
•
Displayed '--' and A/C control Module regards and controls it as 20℃(68℉) |
Temperature(℃/℉) | Resistance(㏀) | Temperature(℃/℉) | Resistance(㏀) |
-20/-4 | 284.5 | 50/122 | 10.8 |
0/32 | 97.5 | 70/158 | 5.2 |
25/77 | 30 |
