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?

 

This has happened to my H2 also- Occurs randomly at start up (if vehicle has been sitting overnight minimum w/ full cooldown). I replaced both sensors, made no difference. Just occurred to me that this started occurring AFTER I replaced the HVAC controller with a new Dorman one. It goes away after start up, about 15 seconds it shows on dash screen and I do not see it again until occasional 1st start ups after total vehicle cool down. Thanks for posting the above detailing of the HVAC being in line to control that dash "ICE POSSIBLE" messaging. I am sure now its just a slight software issue in the Dorman controller. Everything works perfectly regarding AC, so I will let this sleeping dog lie....... It has a chilling mental effect on me when its 90+ degrees of Louisiana heat with 90% humidity and I see that message.....

 

Mine turned out to be some corrosion on the ground terminal the front of the frame rail on the driver side. But yeah, I've heard more than once about the dorman replacement module causing the issue as well. Friend of the dealer told me they will use the doorman units because the OEM are no longer available, and sometimes they have to go through four or five units till they get one that works correctly.