 
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 B1237 if Ambient sensor has been detected below 0.1V for 4 seconds.
| Item | Detecting Condition | Possible Cause | 
| DTC Strategy | 
										•
									 Voltage check | 1. Short in signal circuit 2. Faulty Ambient Sensor 3. Faulty A/C control Module | 
| Enable Conditions | 
										•
									 Ignition ON | |
| Threshold value | 
										•
									 Ambient sensor has been dtected 0.1V 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 |