NHTSA Complaint #11484756 — 2020 CHEVROLET TRAX

This is the 3rd time this has happened in our vehicle, my second complaint here. I was driving on the interstate at posted limit of 60 when brakes began locking up on me. I got it off to the side of the road, I thought my car was going to flip over the brakes locked down so hard. Service stabilitrak light came on, abs light and traction control light came on. I called the dealership who told me onstar provided the stabilitrak code for it. They told me it would be 160 to have it hooked up to diagnostics, that if it isn't covered by warranty it is a customer assumed cost. My husband replaced the ignition coil and spark plugs thinking that it was the problem, well over 200.00 for parts. The car is now doing the same thing, but I noticed it happened an incline, then realized it happened the 1st and 2nd time on a decline. I am now wondering if the transmission isn't going out at 47,363 odometer miles. The dealership is no help, they have the actual codes but won't provide them or tell me what's wrong. All I know is that for a 25,000 k car, it's dangerous. I am lucky I was able to maintain control of the vehicle on an interstate highway.