My "Check Engin" light came on today. I opened the hood to find that
when i got the oil changed about a month ago, they didnt put the
radiator overfill cap back on so the take was neerly empty. I fill the
radiator up to the correct fill line but the light is on. My thoughts
are that I would need to reset the error code in the computer but am
unsure exactly how to do this. I new with older model cars, you just
had to take a paper click and push it into reset button. I have never
accually done this. Does anyone know how and where to reset the error
code without having to take it into the shop.

 

If you have a local Auto Zone they will read the codes for you. You need to
see what the code is to determine the area of trouble I don't see the
overflow tank causing check engine light. Anything is possible

 

If the lamp was coming on because your car was overheating, you shouldn't
have any problems with disconnecting the battery for a few minutes to
clear the code.

If you don't think you lost enough coolant to cause the car to overheat,
and I don't think you should overheat just from not having the reservoir
cap off, you should have the codes checked.