2012 Hyundai Sonata Hybrid: adaptive cruise control problems

Filed May 23, 2016 · Engine · 69,000 miles · TX

My vehicle blew a piston rod while I was driving down the highway on cruise control doing 2000 RPM's. I have always kept up on the maintenance with this car but when I had it towed to the dealership they are saying that it was my fault. They do have an open recall on my year, make, model and engine size but not my VIN. I have done my research online and I have found other cases like this. The car only has 69,000 miles on it.

Filed Dec 1, 2015 · Acceleration · 51,000 miles · NC

While on cruise control at 68mph I was going down a small hill & my car suddenly accelerated from 68mph to 82mph at which point I disengaged my cruise control & the car decelerated . I noted the mileage & took the car to hyundai. They found no abnormal event in the computer log.this begs the issue that I did have this event occur. I had the compute microcode upgraded to the last rev earlier this year.

Filed Apr 24, 2014 · Brakes · 6,700 miles · IL

I was driving at about 55 MPH on the expressway with the cruise control engaged. Suddenly there was a loud dinning and the panel on the dash flashed "hybrid safety warning", "brake failure". The care would not accelerate. I was able to pull over onto the shoulder. The car would not go over 5 MPH. I pulled off of the expressway as best I could. I then shut the engine down. I restarted the engine and the warning was gone. I took side roads home, but the warning did not return. The total failure of engine power was a very dangerous situation. I took the car in to the dealer on 4/21/14. They have not returned it to me. As of today 4/24/14.

Filed Jan 13, 2014 · Acceleration, Electrical · 8,700 miles · CT

Electrical smell like melting plastic wiring: first incident as noted above; 2nd incident on 1/29/2013, mileage 9227-on vehicle start up (engine warm as it was after earlier driving) same hot, melting wire type smell coming through climate control dash vents; 3rd incident on 4/12/2013-mileage 12,353-hot burning smell through heater vents occurring on/after climbing steep hill for a mile or so; 4th incident-4/16/2013, mileage 12538, location of incident same as 3rd incident, same hill climb, same smell occurring during drive. Reported to dealer. Could not be duplicated during service appt. No further incidents of burning smell to current date: 01/13/2014. Cruise control and transmission gear selection issues: first incident: around 1/20/2013; subsequent incidents periodically since then to current date of 01/14/2013: when on cruise control, speeds set at anywhere (40-60 mpg for these incidents), on coasting down or flat terrain transmission will shift from 6th (high) gear down to 3rd or 4th and hold that gear with engine rev ving accordingly, until I either manu-shift it back up to 6th, or, perhaps after 10 or more seconds it might shift into higher gear on its own. I have deliberately not disengaged cruise control during these incidents to continue to assess the condition. Related to this is occasional excessive acceleration as car can drop (on cruise) to below set speed as in a dip in the road, and then applying speed to get back to set speed, but, it will accelerate aggressively to as much as 10 MPH above set speed before cruise control mode 'back' off the acceleration action, making the car feel like it is 'taking off'. This can happen often on certain roads at same transition points from coasting downward into a dip in the road, then (cruise control) reapplying power to get the car backup to speed. Rest will be sent in a second submission following this.

Filed Jan 13, 2014 · Acceleration, Transmission · 8,900 miles · CT

See submission number 10559603 sent prior to this on 1/14/2014: this is a continuation of the explanation of the cruise control/transmission/power train issue experienced with the vehicle since new. The text from that submission continues to its end. "it would appear that the cruise control/power train computer program has some errors in it or needs updating to correct the problem of excessive acceleration when re-attaining a set speed from a coast down that causes the car to go below the set speed before the sensors detect and activate the acceleration required to bring the car back up to the set speed. Then is 'shoots' the car forward at full power-like unintended acceleration might- and send it up to as much as 10 MPH above the 'then set' speed I have desired. If there is a corner at the end of the rise, the car can feel out of control during this acceleration as it is at full power during the acceleration phase. The transmission also down shifts 2 or 3 gears during this process which aggravates the fierce acceleration feeling. These incidents have been reported both to the hyundai dealer and to hyundai. Hyundai says, take it to our dealer; the dealer says they can find nothing wrong as no dash warning lights are ever showing and their electronic scanning brings up nothing of any kind of problem. This may or may not be exclusive to the sonata hybrid with cruise control and since many people do not use cruise control on winding rural roads, they may not/never experience the same sensation that can happen often to me. I can deal with it. The federal safety agency should keep this report on file in case other cruise control or acceleration issues with hyundai vehicles surface as my report is precisely defined as to what type of road condition it occurs on and what happens. Thank you.