Hi folks, and happy holidays! I am new here and hope I am doing this properly. Following is what I am hoping someone can help with re: guidance;

We recently bought a used 2003 Sonata, which seemed to be in good shape and with relatively low mileage.

Just yesterday, for the first time,the auto transmission began occasionally shifting quite aggressively between gears without any prompting with the gas pedal, and the check engine light came on. No signs of engine overheating or any other warning lights/signals. My wife and I are clueless about what might be causing this. Could it simply be a matter that it is low on transmission fluid, even though no pre-warning lights have been present, or is it a sign that the tranny is shot, or? Generally, in the 4 months we have owned it, it has run perfectly and changed gears smoothly until yesterday. Does anyone have any opinion or suggestions? Unfortunately, we cannot afford the expense of taking it to a dealer for their opinion on what might be wrong. Any help or guidance here would be HUGELY appreciated, and is it unsafe to drive until we know the problem, and would driving it somewhere to have it fixed possibly cause more dramatic damage? Thanks in advance to all respondents!

 

Code reader to check diagnostic trouble codes.
Has the gear selector gotten loose?

 

Hi and thanks for reply. i don't know how to read diagnostic codes (and have no manual), and don't believe gear selector is loose (certainly isn't at shifter console) but not aware of how to check/confirm.

 

Only you know how feasable the following suggestion might be, but consider this.
First check the trans fluid level with the engine warmed up at idle,and the trans in park. Smell the dipstick. If the fluid smells burnt or not. Harsh shifts do not usually cause fluid to get overheated only slipping does that.
Places like Autozone, Advanced Auto, etc will usually check your vehicle for codes at no cost. If not too far , worth the trip.They might be able to tell you what the code(s) mean. If not, post it/them here, we might be able to help.If you take it easy can you do that?

 

Thanks so much for the reply. Did check fluid level as you said. Definately below the hot/fill level but still a fair bit evident. Did not smell the dip stick but we have regularly noticed a burnt smell when car has been running for a while, although never any signs of overheating on the guages. And the only warning light we have seen was yesterday when the check engine light came on, for 1st time.. No code was shown ane we don't know how to find/determine if one exists. We are from Vancouver Canada, and I am unable to locate a company that will diagnose/find code without a significant charge. Any other suggestions on how I might figure out what is wrong. Happy to add fluid, or even do a flush, new fluid add, but can't afford to spend several hundred dollars, if the tranny turns out to be garbage, as we would need to find another vehicle.

 

The cause for the check engine light is the better way to start going after the problem.
It could be something simple, but the code would provide some direction. Each individual item would have to be checked and that could take a lot of time and $$$..
To assume the worst is not always a good thing. Check around and inquire what a shop would charge to check for the codes.
If we take these things one at a time without jumping into things, is usually the better and most economical way to approach this.
Once we have the code or codes we get some idea of where to start checking, and go from there. Don't be discouraged, as stated earlier , it could be something simple.

 

Thanks Hanky. I will be pursuing your suggestions, and others, today. Cheers!

 

If it turns out a trans fluid flush and replace will do the trick, should I replace the filter at the same time? If so, is there a certain type of filter I shoul use?

 

The idea here is to go after the real cause of the problem. The code(s) should provide the area our efforts might be directed upon.

Hoping to correct the problem by changing the fluid and filter may not be very helpful here. You can try that. If the condition of the fluid is OK , don't know at this time.
Most auto supply stores NAPA, Autozone should carry the filter and the correct fluid.
I do not know if there is something like an Autozone store near you, but most of them will check your vehicle for codes at no cost. Not sure if the same in your area.
It is a challenging decision to pay to get the code(s) or changing the fluid and filter. From my experience I would try to get the code, then decide if we wanted to repair it or try changing the fluid and filter. If it is the type repair that requires getting into the trans, the fluid and filter would be changed at that time.

 

Thanks Hanky. Where i am from, there is no free code reading. Avg code read is &75 -100, or buy a reader. Am taking your advice and trying to determine code status before flush/replace is considered, but something is definately making the gears change a bit on ther own. Will check in tomorrow after I know a little more.