Transmission Location on 2002 Hyundai Elantra GLS?

Your FIRST mistake was taking the car to a TIRE shop to get it checked out. NEVER take it to ANY business that has the name of a tire on the roof.

Take it to a shop that specializes in your brand, OR the dealer as a last resort.

If you continue to drive it with the check engine light on, it will eventually stop running, so get it fixed now before you have to have it towed.

The transmission is to the left of the engine itself pretty hard to miss really, unless its like some Honda's and Mitsubishi's then it might be on the right of the engine.

EDIT: What transmission is it, is it manual or automatic?

EDIT: I think I'd just take it to a reputable garage and have them look at it

There is no dipstick above the transmission there will be a big nut to the back that you remove and there will be a small dipstick attached to it that is where you check and fill it... it's a pain in the butt

look around under the hood ! if it has a stick then it should say ( trans fluid ) on the stick handle ! just watch you don,t overfill it !