Honda Accord 2003 sedan, Check engine light on and transmission is not smooth

Hi
My honda accord 2003, 4 cylinder (101000 miles) has constantly check engine light on, also transmission has been rough (it started right after a trip to mountains). The transmission sometimes becomes smooth as normal but still check engine light on and most of times transmission is jerky. I took it to mechanic, he did testing and there was no code. I have no idea whats wrong in my car and how to get it fixed?
Thanks

If the check engine light is on, there is at least one code. Get the code(s) and let us know what they are. The transmission is may be different. When is the last time the transmission fluid was changed?

I had my transmission fluid change may be a year ago at around 90K miles.

Go to someone that understands that if the check engine light is on there is a code set. Apparently who ever you went to does not understand this, doesn’t have the equipment to read a trans code or just doesn’t want to deal with an auto trans problem.

Thanks, I will get the code re checked! In fact he suggested me to do a software update from honda dealer and said most likely it will solve the problem.

It sounds like he doesn’t even have a scanner. If he’s just pushing you to the dealer.

Yosemite

When you had your ATF changed, did the use only Honda ATF? This transmission is very sensitive to the ATF used, anything else will result in hard shifting and other problems.

If you have a CEL, you have a code. It may be a manufacturers specific code that a generic code reader can’t read. If your D4 light is blinking when you put the vehicle in gear, you have a transmission related code.

Thanks Keith,
My D4 light is not on. And i had my ATF changed at honda dealer`s shop ( i hate this dealership).

Also, Last year (from may through august) i went to my home country and was stuck there for 4 months, during that period my car was sitting idle, leading to bad battery. I got new batteries (at honda dealer) but my car was behaving weired with engine RPM go high and low automatically even without pushing the gas padle. But this problem went away in couple of days. Do you think because my car was sitting idle for too long that could have created some issuses that caused some visible probs after several months!!!