In my 2020 Highlander I approached a stop sign at a "T" intersection behind 4 other cars. After stopping and looking to see road was clear of oncoming traffic, I pulled out and started my left turn. As I was turning into my lane the car engine turned OFF and the steering wheel was LOCKED in the left position. There was no power for the brakes, which left me jamming on the brake pedal as hard as I could only slowing the car slightly. The steering wheel was LOCKED LEFT and I thought I was going to break it trying to force it back. With no ability to move the steering wheel or brake, I braced myself as the Highlander continued turning in the left direction into the other lane. The result was a head on collision with a Mini Cooper, both cars totaled, and injuring both myself and the other driver. Highlander was investigated by forensic company in the employ of the insurance company, but they could not find any error in the cars CDR (Crash Data Retrieval) system.