I have a 2012 Sonata Hybrid, and I'm the original owner. 94,000 miles. I was pulling into a parking lot on 09/21/2019 when I had the same problem. Brake pedal went to the floor. Horrible grinding sound from all the wheels. Chiming. Hybrid System Warning. Check Brakes. Parked the car. Got out and looked all around. No leaks. Checked brake fluid level, and it was OK. Turned the car back on and no warnings. Backed car up and no grinding sound. We were out of town and 150 miles from home and nearly as far to the nearest dealer. No problems other than being as nervous as **** for the entire drive.We purchased a 2012 Sonata Hybrid in Sept. 2012. Loved the car and was getting excellent mileage. Traded in my Jetta TDI, so mileage was important to us. Shortly after our puchase we began experiencing intermittent problem with the GPS, radio. When putting the car in reverse, all volume on the radio would quit. Stop car and retry, normally the radio would return to normal. Took to dealer and they said GPS navigation unit/Radio was defective. It was replaced. Within a few weeks of the replacement, the new unit began the exact same problems. Took it back to dealer and said it was doing exactly same, so problem seemed to be electrical not defective unit. Made appointment to have unit replaced the following week. However, later that evening when backing out of a handicapped space at WalMart, the brakes began making serious grinding noise. Could not drive vehicle, so put in drive to pull back into parking space. Vehicle WOULD NOT STOP. Hit concrete post, alert chimes and flashing brake malfunction lights. Used Blue Link to call for assistance. Dealer told us it was a failure of the major hydraulic system. We were met by customer service who convinced us to trade in vehicle. Hyundai hired engineer firm to examine vehicle. said they could find no problem. However, service manager said the hydraulic had failed and the engineer said he could find nothing to dispute our facts of the accident. Hyundai refuses to do anything. Has anyone lese experienced problems with Sonata brakes?
Called the dealer. Hybrid mechanic was in and near the phone. Sounded like he never encountered this problem before. Told me to check brake fluid. Turn car off and on. Already did all that. Took the car to a local brake shop. Check out for leaks etc. Checked computer for codes. Everything checked out. Reluctant to go to dealer which is 40 miles away because they'll just start replacing parts like master cylinder at $500 and the hydraulic power unit for $1500 plus labor ?. Who knows, the sky's the limit.
Like one of the previous post ... What do you do when you're driving down the highway on a steep hill at 75 MPH and the same thing happens???