Ambient Temp Issues - Alfaobd / Help Needed

[octomodz]

I have searched and read through the forums and alfaobd thread. I have a 2015 1500 Eco diesel. I keep getting -40, windows work intermittently or not at all, ac will not work due to the -40.

If I remove the positive battery cable, the windows will work fine for about 15-30 seconds, then temp changes to -40 and they either dont work at all, or barely (small movements with each push).

I have got another door module and this did not fix the issue. for a few days, if I removed the pos bat cable the sensor, windows, ac would work until I turned truck off and back now. Now they only function for about 15-30 seconds.

I have the newer tow mirrors which I believe are from another truck. I have tried using Alfaobd to set to DCM and to set to No on CBC present. This has not made a difference. I tried connecting to the door module with my EX but it will not connect. Do I need the can analyzer that connects to h/l for this? What two pins are h and l from the obd.

Anyone have any other suggestions or thoughts?

I have codes on BCM for comm lost for hvac, door, and one other item (will have to check).

 

[octomodz]

No one at all?

 

[1999 White C5 Coupe]

My only suggestion would be to replace the ambient temperature sensor, and examine the connector for corrosion.

You may be erasing stored trouble codes when disconnecting the battery?

Retrieving the stored trouble codes will begin to point you in the right direction.

You may have a bad battery which is causing some of your electrical issues (such as a bad cell).

 

[chopperman1]

The temp sensor is built in to the drivers side mirror. Try putting your OEM one back in as a test to see if that resolves it.

 

[1999 White C5 Coupe]

I have searched and read through the forums and alfaobd thread. I have a 2015 1500 Eco diesel. I keep getting -40, windows work intermittently or not at all, ac will not work due to the -40.

If I remove the positive battery cable, the windows will work fine for about 15-30 seconds, then temp changes to -40 and they either dont work at all, or barely (small movements with each push).

I have got another door module and this did not fix the issue. for a few days, if I removed the pos bat cable the sensor, windows, ac would work until I turned truck off and back now. Now they only function for about 15-30 seconds.

I have the newer tow mirrors which I believe are from another truck. I have tried using Alfaobd to set to DCM and to set to No on CBC present. This has not made a difference. I tried connecting to the door module with my EX but it will not connect. Do I need the can analyzer that connects to h/l for this? What two pins are h and l from the obd.

Anyone have any other suggestions or thoughts?

I have codes on BCM for comm lost for hvac, door, and one other item (will have to check).

What did you determine or resolve?

 

[JmGuTe]

As stated the -40 is because the ECU cannot "talk" with the ambient temp sensor. The ambient temp sensor can be replaced by itself without having to replace the entire mirror. Just get a trim tool and pry around the edge and it will pop out. Several youtube videos on it.