2013 Cadillac xts ambient temp not reading

Pierre Mechanic Texas Posted   Latest   Edited  
Unsolved
Electrical
HVAC
2013 Cadillac XTS Platinum 3.6L (3 LFX) 6-spd (6T70)
Ac Inoperative
Not Reading Ambient Temp

Have a 2013 Cadillac XTS platinum 3.6

noticed ac will not work when car doesn’t read ambient temp when car is started sometimes it’ll show -40 degrees on cue screen and other time it’ll show - - I can turn ac on but clutch will not engage and will not cool, refrigerant pressure are at spec, while I drive over 60mph temp will start reading and rising as long as I maintain speed, and when it does begin to read, ac will start to cool, once I slow down or come to a stop temp will drop down to 0 then -negative 40 and then will just show 2 lines and ac will cut off, replaced ambient temp sensor with a new oem acdelco sensor and problem continue, any ideas or things to check?

Tia

0
Dan Technician
Ontario
Dan
 

Hi tia with the sensor unplugged did you measure the voltage on both wires ?

+1
Ð Awarded
Helpful
Matthew Technician
Nova Scotia
Matthew
 

Interesting problem. I'm curious if you were able to pull any trouble codes? A quick look at the system design shows the ambient temperature sensor is used for a display in the instrument cluster. I don't see the connection to the A/C system. The A/C system appears to use a combination of duct temperature sensors, windshield temperature sensor and sun load sensor.

0
Ð Awarded
Bill Owner
Nevada
Bill
 

Definitely check the wiring to the ambient sensor, I have come across this issue. If the ambient temperature is freezing, there's no point in turning on the A/C so the car won't.

0
Ð Awarded
Matt Technician
Saskatchewan
Matt
   

Check this recall out...

0
Ð Awarded
Bill Owner
Nevada
Bill
 

That recall stated a 10-20 degree variance from actual. This vehicle has a reading of -40 degrees, which is below freezing when the outside air is at least +75 or higher. That's a variance of 115 degrees. Not stating that the recall won't help, but I tend to follow the details when reading a TSB. (I assume +75 hot enough for A/C)

0
Ð Awarded
Matt Technician
Saskatchewan
Matt
 

I’m aware of those ”details“, I just thought that this recall was very specific. “2013 XTS“, no other years apply. As for the “details“ in Pierre‘s post, he does say that the temperature changes as he’s driving. Maybe it comes close to that 10-20F difference at that time? I’m not sure. Either way, if that vehicles VIN applies to the recall it should be performed.

0
Ð Awarded
Mike Owner/Technician
New Jersey
Mike
 

I know this will sound crazy but... I had the same issue with a 2015 GMC Sierra pick up. Couldn't talk to ambient temp sensor. Customer was standing next to me and said try disconnecting the battery and touching terminals together...I thought no chance that will work but I'll give it a try to appease him. I did it and it worked...can't hurt to try. I have done this on 2 other GM vehicles and…

0
Ð Awarded
Pierre Mechanic
Texas
Pierre
 

Anyone have a wiring diagram for the wiring harness in the front bumper and specifically the pin out on the connector for the harness, found the fault but a few of the wires are the same colors and I can’t tell which one is to ambient sensor or park assist sensors

0
Ð Awarded
Bill Owner
Nevada
Bill
   

Here you go Goodness, that sensor has quite a few failure points. Instrument cluster (X1) > x210 > x150 > x105 > Sensor. Good luck!

0
Ð Awarded