Just replaced both sensors up front passenger side bumper area and looks like the front sensor connection is not seeing the new sensors this has taken out my AC like its supposed to happen. My question is “where and what do i check now ???? The contacts seem to be fine i also have a Tech2 but don’t know what menu to get to check the sensors??? Anyj ideas???

 

Did you scan & get B0159?

Circuit Description

The ambient air temperature sensor allows the HVAC control module to monitor the temperature of the air
surrounding the front of the vehicle. The module applies 5 volts to internal input resistors that are connected to
the signal circuit of the ambient air temperature sensor. The module provides ground to the ambient air
temperature sensor through the low reference circuit. The HVAC control module monitors the voltage drop
across the ambient air temperature sensor and uses the input for automatic control calculations. When the air
temperature is cold, the resistance of the sensor is high and the voltage signal is high. When the air temperature
is hot, the resistance of the sensor is low and the voltage signal is low.

Conditions for Setting the DTC

The HVAC control module determines that the voltage applied to the input for the ambient air temperature
sensor is less than 0.09 V or greater than 4.9 V.

Did you reset HVAC?

 

Hopefully you've fixed the problem.

One of the sensors links to the HVAC and cab be displayed On the Tech2, the other connects to the internal mirror is there is no link to the OBD2 bus.

The sensors are negative temperature co-efficient i.e. the higher the temperature the lower the resistance so if the sensor was open circuit you would get "Ice Possible"

It seems to take a long time to recover from an open circuit, several hours as I recall.

 

hmer "JUST REPLACED" the sensors LAST YEAR! Now, trying to cash in on a new YT video to make up for previous error?