2001 Hyundai Accent high rpms on highway

You need to make sure your trans is shifting to high gear. if not thats why your rpm's are to high.

Hi i have a 2002 hyundai accent GL 2.6L straight 4,my ****** will shift into overdrive but instantly shift back to third gear. My ****** fluid is full and is clean and pink.i always drive in third gear with overdrive off and as of today 03/23/12 my third gear is slipping, when i floor it it bearly even goes any where. I also put a quart of ****** fluid so my ****** is overfilled by a quart and this solved the slipping in third and it acclerats normal.i realized that it was over full after i put the fluid in.I put fluid in cuz i seen alot of ****** fluid leaking, it was puddled on top of the ****** so thats y i put a quart of fluid. I am so lost on my ****** can anyone explain whats going on here? ive done 5 years of auto mech. so im surprized im lost i usally know what to do=[

I was having this problem when I first got my Accent GS.....

Similar to mkv said, make sure that it is getting to the high gear. The problem that I was having, is that I had never had an OverDrive vehicle before, so I had it it turned off, and it was only going through 4 out of the 5 gears. By turning on the OD, it allowed the Automatic Transmission to go into 5th gear. The first thing that I would recommend is to make sure that your OD is ON. On your Automatic shift knob, there is the larger button to switch through P,R,N,D,2, and 1, and below that is a small button... make sure that the smaller button (OD) is engaged. If you already have OD on, then again, as mkv said, without seeing it, that is a tough one. I hope this helps your problem.