2019 gmc sierra park assist only working under 50 degrees.

[KShi]

Has anyone had the problem of their park assist only working in cold weather. I found out that it only works if the temperature is 50 degrees Fahrenheit or lower. Works all winter but never in summer. Was just curious if anyone has ran into this problem or suggestions on what might cause this problem.  

[hoitzed]

Same issue here on my 2019 AT4.  Dealer did a diagnose on it and said it was a faulty sensor.  Part is cheap ($150~) up here, but labor was a killer, I think they quoted 3 hours ($500+).  The sensors don't come painted, so they need to hit the paint shop, and the entire bumper, grille, and most of the front needs to be disassembled to get to it.  I'm not sure about yours, but my faulty sensor seems to wiggle by a small amount, compared to the others that are a tight fit.  Not sure if that has anything to do with it.  The dealer just chalked it up to "maybe a piece of gravel hit it" etc etc...