2003 elantra gt automatic transmission is shifting hard

SOURCE: transmission/shifting 2001 Sante Fe - Hyundai

Sounds like you might have serious internal transmission problems.

As soon as you can, get someone with a code reader to plug in the vehicle and find out what the code is for the Check Engine light to come on. Might give you a better picture of what`s going on.

It could also (cross your fingers) be something more usual like a clogged transmission filter (located inside the pan), or shift solenoid.

By the way, have you checked the level, look & smell of your transmission fluid?

Level should be checked with the vehicle running, after passing it in all gear ranges on the shifter, and putting it back in park (Check it on "cold" or "hot" level depending on if it`s been driving for a while or not).

As for look and smell, it should be reddish and not smell burnt. Hard to describe the smell of burnt transmission fluid, but normal fluid does not smell too strongly, kind of sweet. Burnt oil is usually black and has a strong odor. If the oil is burnt you have internal damage to the transmission.

One piece of advice I give you is get it fixed as soon as possible because if you don`t already have serious internal transmission problems, the longer you wait, the more chances you have of getting some, to the point of the vehicle just refusing to move. And believe me, speaking from experience, the transition point from the symptoms you describe to total refusal to move and the need for a tow/transmission rebuild is not that long usually.

SOURCE: 1990 ford econoline van trans problem

Check tv cable, from throttle body to trans.

SOURCE: Rough shifting automatic transmission on Honda Accord from 1st to 2nd gear

it has a problem with the second gear drum it cracks and does not fully engauge the n shifts to 3rd ..many honda owners also learn the 8 bucks a quart is the only fluid to pour in a honda..but remember 3 qaurts per drain and fill the tranny holds 7q ....it will take a case to do a drain flush...a high pressure flush will ruin a automatic tranny with alot of miles or metal deposits floating around inside..DRAIN AND FILL 3 QUARTS AT A TIME NO GASKET NEEDED ITS BUILT AND DESIGNED LIKE A MANUAL TRANNY

SOURCE: 2000 Hyundai elantra transmission delay, reverse going

Did you check the transmission fluid level? If necessary, add fluid. However you probably have a more serious problem. Take the car to a qualified transmission mechanic.

SOURCE: 2002 Grand Am GT transmission problem.

Well, there could be several possible problems. It is not uncommon to have a little harder shifting after a fluid change for a period if the system was low prior to the change however, If you had the fluid changed using one of those reverse flush machines I see the problem getting worse. Most stations want to use the back flush system to do a fluid change now days. That is because the newer model vehicle have a metal filter screen which is re-usable and is designed at the factory to use Synthetic Fluid. In the older model vehicles, 2000 to 2005, manufacturers where still mixing the types of filters that were being used. This model has a standard filter that model uses the newer filter. If you went to Jiffy Lube and didn't specify you wanted a regular Fluid and Filter change they hooked it to the machine and charged $140+ for the job. A regular Filter and fluid change with regular fluid would have run about $50. Every time, and I mean Every time, I have had a fluid change using that back flush machine on a vehicle within 6 months I have had to have the Transmission repaired at a shop. If you didn't have the fluid changed using that backflush machine then your problem is just adjustment to the new fluid being at the proper level. If you did, start saving for a Transmission rebuild at a shop, it's not far away.