Huge win for car owners! All TSBs to be made public. The Center for Auto Safety just made the NHTSA (US Government) make public the full text of all TSBs from now on. They are the same organization that has petitioned the NHTSA & filed lawsuits to protect car owners over exploding gas tanks & other major safety issues. Whenever you drive in your car, you are safer thanks in part to a lot of work over the years by this small but very effective consumer advocacy group.

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definitely annoying
Crashes / Fires:
0 / 0
Injuries / Deaths:
0 / 0
Average Mileage:
28,825 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2012 Hyundai Sonata Hybrid engine problems

engine problem

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2012 Hyundai Sonata Hybrid Owner Comments

problem #6

Nov 272015

Sonata Hybrid

  • 51,000 miles


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.

- Durham, NC, USA

problem #5

Nov 292014

Sonata Hybrid 4-cyl

  • 74,000 miles
This problem has been getting progressively worse during the last 6 months. While driving or stopped at a light, the vehicle has sudden unexplained acceleration. The acceleration happens with or without the foot on the gas. When in drive, the driver can remove his foot from the gas and the vehicle continues to accelerate and pick up speed. The condition is extremely hazardous and warrants further investigation.

- Tijeras, NM, USA

problem #4

Jul 012014

Sonata Hybrid

  • 30,000 miles
Gas pedal on car sticks and stays in acceleration increasing speed. Have to manually pull gas pedal back up from behind pedal. Took to dealer to inspect since they haven't been able to duplicate issue did not fix and if there was an issue it wouldn't be covered under any warranty?

- Albuquerque, NM, USA

problem #3

Nov 082012

Sonata Hybrid 4-cyl

  • 350 miles


When accelerating from a stop, the vehicle takes excessively long time to go from 0-25 mph, so much so, that when merging into traffic it has unpredictable acceleration. At various times I would step on the gas pedal and sometimes it would have a 3-5 second delay before going forward. When it finally accelerates sometimes it has a popping sound and often the car lurches. I have brought it in 3 times for Hyundai to find the problem but each and every time they have said they were not able to find anything wrong with the car.

- Garden Grove, CA, USA

problem #2

Jan 202013

Sonata Hybrid 4-cyl

  • 8,900 miles
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. NHTSA 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.

- Sharon, CT, USA

problem #1

Jan 202013

Sonata Hybrid 4-cyl

  • 8,700 miles
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.

- Sharon, CT, USA

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