Two problems related to owners/service manual have been reported for the 2012 Hyundai Sonata. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2012 Hyundai Sonata based on all problems reported for the 2012 Sonata.
Key fob in 2012 Hyundai Sonatas not recognized and don't allow you to start up your car using the push/start button; also, doors won't unlock with fob and manually have to be entered using actual key. Seems like some programming to the fob has been lost; dashboard would turn on and say"key not in vehicle" or "insert key" when depressing the push/start button. Apparently, dealerships are aware of the problem, but may not actually report it and treat as something else only after numerous other repairs. Youtube videos of these issues as I've described are available. Vehicle is stationery when this happens; then it would work and then stop again in a few days. Changed batteries in both fobs and still the same issue. Originally starting happening a week prior to 9/27/2018.
The vehicle has a history of losing power completely. At this point I am unable to enter the car with the keyless entry, you have to do it manually. The car was parked on the street. Once you put the key in the ignition the horn/alarm goes off and doesn't stop. It also seems to be revving while it is in park. While driving I experience little power surges from the car where it accelerates with me trying to do anything. There was also another instance where the car would not start once the emergency brake was engaged. Once disengaged the car started with a little hesitation. I only had the car for 6 months and have had to bring it back to the dealer at least 6 times.