2021 CADILLAC ESCALADE ESV Forward Collision Avoidance Automatic Emergency Braking Problems

Back in August of 2022 my 2021 Cadillac Escalade started having severe engine roughness, a check engine light, and an error saying that most of the collision safety features had been disabled. I was able to limp the vehicle into a GMC dealer who informed me that Cadillac had received a bad shipment of lifters and that one or more of the lifters had broken. When the vehicle detects an engine problem, it apparently disables most systems in the car. The GMC deal had the car for weeks trying to repair. They told me that Cadillac only authorized replacing 1/2 of the lifters. Since that time, the vehicle has continued to idle very rough ; the RPMs fluctuate and power surges at idle and while driving. I have been attempting to reach the Cadillac customer service people, am routinely told that I'll receive a call back "within 2 business days"...