2019 Cadillac XT5 Steering

We got the message that our steering may be impacted and then our temperature gauge wasn’t working nor the stop/start feature. Trip to service dealer resulted in a $1,186.14 repair for the replacement of the thermostat. This car only has 37,269 miles. We were told by service tech this is a common issue in GM models and this year of car. This was a financial hardship on us and our well maintained, and rarely used, vehicle. How can GM know this is an issue and not offer remedy thru a recall?

Steering assist disengaged, low power mode, no temperature read and check engine light. All occurred at 61k miles.

Georgia

Message Displayed on 2019 Cadillac XT-5 "Steering Assist is Reduced - Drive With Care". No check engine light, and no apparent loss of steering. Noted that Temperature Gauge and Air Conditioning ceased to work. Suspiciously, a 2017 Cadillac XT-5 that I also own, the identical displayed message came on, with identical same mechanical issue, and just learned that an acquaintance with a newer Chevy Blazer just experienced the identical issue also. All vehicles are equipped with OnStar. Coincidence, OR any possibility that GM or OnStar computers have been hacked into, as OnStar has ability to control various functions of vehicles. To correct the issue (possibly only temporary) was to remove the negative battery cable for a short time, and reattach.

My vehicle is receiving a notice "Steer Assist is Reduced Drive with Care". Per discussion with the dealership this is a result of a thermostat issue causing an issue with the grease temperature in the steering. Based on a bulletin to the dealerships from 2017 this is a known issue and continues to be a known issue for multiple GM vehicles. GM can not supply new thermostats to dealerships and they are just resetting the warning. Steering is a critical issue and GM is aware of an issue and is not recalling or repairing timely.