[awould]

My 2009 Sonata Ltd has a problem. When I'm cruising down hills at about 70mph and tap the brake, the car jolts. It doesn't feel like a brake issue, but a transmission issue. Like it's trying to switch gears right as I hit the brake and it sort of lurches or jolts. It's not subtle and it doesn't feel safe.

Sadly, my mechanic at the dealer is unable to offer any ideas since they can't experience it firsthand because driving 70mph exceeds the speed limit and they can't break the law, and besides, there are no hills in Phoenix. Or so they say. It typically happens on drives down to Phoenix from Flagstaff or Payson, for those familiar with the area.... curvy mountain freeways.

Any ideas? I get the feeling when the problem persists to the point where the car's computer acknowledges the problem, it will be out of warranty. As it stands, I feel like I'll have to hold somebody hostage or sue somebody to get them to investigate it and fix it.

 

[Djonemore]

I know the feeling with my 07, it feels like a manual and the TQ converter stays locked... When you take your foot off the petal to slow down or go to tap the brake do the rpms stay about the same? I had the same issue with mine dealer told me it was normal, until the check engine light went on and they replaced the "Throttle Position Sensor" which fixed the problem, at all speeds.

Before the "TPS" went bad I had a quick fix to the issue, just as your about to let off the accelerator slam it to the floor (really quickly) and let go it will make your transmission believe it's about to get ready to shift and unlock the tq converter which will drop your rpm down and you wont feel the jolt.