After driving about 20 minutes one or both front tire pressures will fall off to "--". Sometimes one then the other. sometimes within an additional 20 minutes they will self relearn and the warning goes off. Other times the warning and reading stays on until next start and drive. I had no issues last summer(my first summer with the car). I have replaced all 4 sensors with new GM parts with no change. I have been to my dealer to have them reprogrammed twice with no change. I have purchased a cheap programmer which will "force" the relearn but the symptom doesn't change. The self learn does work because if the car sits for a few days the warnings are off when first start and drive. Over the winter I added a wireless car play adaptor, "true" forged wheels, and replacement LED tail lamps. I have tried disconnecting the car play adaptor and no change. When it happens it is daytime and no outside vehicle lights are on(thinking the tail lights may cause it but not when off?). I turn off auto lamp feature as soon as I start the engine every time. Any suggestions would be helpful as the car will not allow any medium to hard cornering with the tire warning on. Some other threads have suggested a way thru multiple traction button pushing to cancel tpms for 1 key cycle but the method doesn't work on my car. I want to do a track event but will need to fix this first. 2017 grand sport

 

Have you updated the front side markers with aftermarket

 

no side markers replaced. Factory still. No other changes to the car other than mentioned in post.

 

Did you scan for codes with a code reader that can read modules, it sounds like a communications issue on the CanBus for the TPMS sensors ??

Dave

 

I purchased 4 sensors from the seller AutoParts771 on EBay. They offered OEM replacement sensors with the correct hertz rating, and have the all black stems to match my new Wheel Designers ZE11 wheels.
The tire pressures were displayed within a few miles of driving.
Cost was $98.99 for a set of 4.

 

Yes, replace the sensors and see if that fixes it; I suspect it will.

 

Doesn’t seem like anything you have done to the car would be the cause of the sensors displaying incorrectly so it may just be the sensors themselves.

 

I am experiencing the same problem on my 16. Sensors were changed with GM parts and that did not fix it. An occasional bump will turn the fronts on then they randomly go back off. Once in a while they are on with startup. Cornering turns the traction control on.
I will be heading to my local shop to see if they can scan the module and following your post. Please keep us updated.

 

thanks for the good info. out for the 2025 season and over this winter I RF insulated the Morimoto tail lights, replaced the TPMS module with an updated gm part. set the wheels out for powder coat for color change, and replaced the sensors for a 3rd time. I always use genuine GM parts.

 

Is it always the front two sensors? Nothing added to the wheel wells?