Hyundai Accent 06 auto trans problem

Hi Everyone,
Dad has a Hyundai Accent that hasn’t had the best service history. After discovering this I started doing minor stuff (oil & filter, spark plugs, etc) on the car. The car has done 119,000km and about 2 months ago I decided to change the auto trans fluid and filter, I don’t think its ever been done before and the fluid was pretty bad. I followed the tutorials exactly and everything was fine until yesterday. It seems the car get stuck in 3rd and downshifts badly when coming to a stop. When I last drove it I got home and quickly opened up the hood. I could see smoke coming from somewhere near the trans and there was a bad smell. We haven’t driven the car since and I don’t know what the problem is. I’ve checked on google and some people have used a scanning tool to get the error code, but the car doesn’t throw a check engine light so will the error code be there? Any advice is greatly appreciate.

Have you rechecked the trans fluid level. When doing the filter and replacing the pan, you may not have gotten the pan sealed correctly and the fluid has leaked out.

Are you positive that you used the correct fluid called for in the owners manual?


A big +1 for Yosemite.

Yes, the pan was sealed correctly and the car hasn’t been leaking. The fluid level is spot on the mark. On google some people say that being stuck in 3rd is the car in limp mode, but again no cel has come on. I used the correct fluid but opted for a fully synthetic fluid by Penrite, as it was compatible from their product selector web site. Further reading, some owners also have had input and output sensor failure which also causes the trans to get stuck in 3rd. But they have used the scanning tool to get the code. I can buy a scanning tool but as posted if the car doesn’t throw a cel will the error code be there?

You may find something in the “History” option on the scanner.


If you didn’t use the SPIII transmission fluid that Hyundai specifies, anything can happen.

Also, if you just did a pan drop when changing the transmission fluid, not all the old transmission fluid was removed. So you now have two different types of transmission fluid in the transmission.

Again, anything can happen.


I never use a transmission fluid that claims to meet the specs of many manufacturers. Use specifically what is called for in the manual. That way, if a problem arises, you know it isn’t the fluid.
Does this car have a drain plug on the transmission? If it does, I would drain and refill with the right fluid, drive it and change again if it still doesn’t drive right. If that doesn’t work, off to a good transmission shop. Not a national chain.

I also flushed the transmission via the return hose from the radiator till the colour of the fluid changed so most of the old fluid was out.

So I had another look at the car this morning. When I pulled the transmission dipstick out I smelt the fluid and it smelt really bad. The colour was ok. I’m still not sure if its the fluid that’s the problem. Could driving the car in 3rd for a few km cause the fluid to burn?

I would have it towed to avoid ant more damage to the transmission. Even mile of driving could do more damage.
Find a good independent transmission shop in your area to drop the pan and check it out.
avoid the chain shops like and find a good independent shop, the chains stores just want to sell a new tranny and many times don’t really repair…just replace.

You may be looking at something simple…maybe they sold you the wrong filter.


Maybe something got dislodged, bent or disconnected during the transmission service

Did the new filter get seated all the way?

I agree with the others . . . I would not have used a generic atf, which claims to meet the specs. Especially if it’s one of those fluids, which claims to meet every spec under the sun

You are checking the fluid level when it’s hot and the engine is idling, yes?

I went to a transmission workshop this morning and the car’s book in for tomorrow. The guy I spoke to seems to think the car is going into limp mode and will scan it and take it from there. I explained the whole story to him and he thinks its an electrical issue.
Thanks everyone for all your help.

Let us know how you make out.

We do care and we may learn something out of the results.