The automatic transmission on my 2004 Elantra GT has a problem where it flips out of gear, loses power, and soon locks up and seizes. I can catch it before it locks up by putting it into neutral and back into drive, but it repeats it. It did it a few weeks ago at higher speeds (60s) after I'd been driving 20-30 minutes, and it threw a 4th-gear ratio code. Transmission place couldn't find anything wrong and couldn't get it to repeat.

It just did it again last week first thing, suddenly cold morning, and I could keep resetting it, but it kept doing it, and I couldn't get more than a block away. After it was towed in, the transmission place couldn't get it to happen again, but they got new codes this time. I don't know the codes, butthey have to do with reverse and with drive at low speeds.

The transmission place is thinking after reading a bulletin that it won't require a full overhaul, butthe bulletinsuggests starting with solenoids, then something else, then something else, all things leading up, if necessary, to the computer. To cut possible losses, the mechanic is going to do the first three suggested repairs at once--about $900. (I'm beyond warranty, by the way. 73000 miles and not the original owner.)

The thing is, of course, you never know that it's fixed. You can only know if it isn't. And you can find out the hard way at a very bad time!

Any suggestions or similar problems?

Thanks.

 

try and get the codes that he retrieved. without that it's just guessing.

 

The code (finally) is P0750.

Any insight is much appreciated. Thanks.

Nora.

 

If you're in the U.S. and the car has less than 60,000 miles on it, you're still under warranty. Get it towed to the nearest Hyundai dealer and have them look at it.

If you got the transmission flushed and didn't use SP-III fluid(as specified in the owners manual), the dealer won't want to fix it under warranty though (improper maintenance). In that case it should be fixed by the transmission place that flushed the tranny on their nickel. If they say they used "universal" fluid, don't believe them; there is no universal fluid approved by Hyundai.

 

po750 is a LR sylenoid valve malfunction which could be a harness problem inside the tranny or a actual valve malfunction. There is a service bulletin that covers this 05-40-006-1 and 05-40-006-2 I would personally have this tsb performed before any further diagnosis.

 

I did understand when I bought the car that the warranty would be up at 60,000 miles, which was 13,000 miles ago. And the Valvoline place did use Dextron, but the tranny guy I took it to doesn't think that's the problem (though he recommends changing to SP-III next time, he wasn't concerned with switching it now. I will when I can.)

Mainly I'm asking if anyone's had a similar experience and whether repairs less than a complete overhaul worked.

 

Yes, that's the bulletin they found at the garage. They did those first three repairs to cut losses on labor and gamble possibly more money than life and limb--I drive interstate a lot.

What's scary is that a number of weeks passed between the first time it happened and this time, and it wouldn't even act up for the mechanic. So I'm trying to glean from personal experience how much to trust the repairs. The next one, I believe, is the computer. The three repairs they just finished yesterday came to $940.