i just bought a 1996 grand cherokeee limited, and the engine light was on, but the dealers mechanic reset it, and it shut off...he said he put in a new battery and that is why it went on, but on my way home, the engine light went back on....does anyone know how to reset this light? Does the dealers story sound believeable?
please help......

I don't think the dealer is right. I believe that the dealer was just trying to get you to buy the suv. I know you just bought the car but do you notice anything wrong with it. Like is it able to stay idle.

it seems to run pretty good, and i was stuck in two hours worth of traffic without a problem (like overheating, or knocking)...it seems pretty powerful also, and it didn't get very hot or anything like that, and no funny noises or smells.....

That is weird that the check engine light comes and after being resetted. Because on my Saturn my light was on and after a month my car would just die after a while of driving and it wouldn't idle right and so i found out it was an 02 sensor. My parents have a Grand Cherokee and they like it but it has had its problems over the years. But the only way to reset your car or at least mine is unhook the battery for a while and then reconnect it and that could reset it.

O yeah check to see when the last oil change was. I know if the oil hasn't been changed before 3000 miles on some cars the check engine light comes on.

the zj has a self diagnostic computer. turn the key from off to on 5 times (not to start!!!), wait a sec or 2, the check engine light will flash, this is a code. The light will flash 1-9 times pause for a sec and flash again 1-9 times, this gives you a 2 digit code. after the first code is done it will pause for a longer time and flash another code if there is more than one problem. If you only get 55 nother is wrong, if you get other codes then 55 singles the end of the diagnostic. 12 is the code for the batter being disconnected within the past 50 cycles.

the Grand Cherokee's check engine light does NOT come on after 3000 miles for an oil change! :grinno: