Hi! Have a year old 2009 Sonata V6... have had problems twice now with the idle and cruise control. Turning the engine on from cold produces an idle which fluctuates between 2000 and 500 rpm, and can stall if a/c is on. This lasts for 5 minutes or until the car has been driven a few minutes.

Brought to dealer, they said it was software problem or a computer chip problem. It was better (not perfect) for 2 weeks after, now 5 weeks later it is just as bad.

Similar problem with cruise control - on flat highways the engine will race and rpm will increase for no reason, then car will pull back to hold to the preset speed.

Car has been regularly maintained by dealership.

Just wondering if anyone has similar problems. Taking it back to dealer again tonight. Don't want it back until it is fixed!

C.

 

Seems to be fixed... dealer said it was the throttle position sensor which affected all three areas.

C.