Check Engine Light On problems of the 2016 Mercedes Benz CLA250

While merging onto the freeway on 1/22/2021 the car's dashboard displayed "collision prevention assist plus inoperative " and the check engine light come on. When this happened, it prevented me from accelerating the car by pushing onto the gas pedal. This caused the car from behind to almost rear ended by car. I was able to drive onto the shoulder of the freeway and exit the freeway. I have taken this car to the mercedes dealership for repair but it is an ongoing issue even after various parts have been replaced.