While driving (usually steady state speed on highway - with or without cruise control engaged) car experiences a sudden loss of engine power accompanied by a jolt (as if brakes had been abruptly and briefly engaged, or as if fuel supply suddenly shut off), tachometer dips suddenly, car suddenly decelerates for a second or two, and then things return to normal. Sometimes an indicator light - or more than one- flashes momentarily at the time of the incident, these include the engine light, the traction control light, and/or the key immobilizer light - sometimes no indicator light flashes at all. This has also happened while accelerating away from a dead stop - sudden loss of forward momentum w/ a jolt. I am afraid I will get rear-ended as the car suddenly slows but brake lights are not illuminated, and a car following too closely will not be able to react in time. If cruise control is engaged at time of incident it becomes disengaged and has to be reset. This sometimes will not occur in an hour of driving, but sometimes will occur as often as 10 times in a 20 mile drive with no discernible pattern. This has happened many times and grown more frequent over time. The first time it occurred was in a rain storm and I suspected the ESC was sensing slippage and firing the brakes, however it happens regardless of weather or road surface and now happens every time I drive for more than a few miles on freeway. The car has been evaluated by Kia service more than three times and problem is not resolved - battery and ABS module were replaced without success. Concern is of safety of vehicle and other vehicles following behind me.

- Sacramento, CA, USA