Join the Car Talk Community!

Discussion Rules

Welcome to the Car Talk Community!

Want to ask a question or join the discussion? Great! Join now.

Sign In Register

How to Reset Check Engine Light

Does anyone out there know how to reset the check engine light on a 2004 Saturn VUE. I had it checked and there are no codes (they ran it twice). Disconnected the battery and yes, that did turn it off, but it came back on this morning.


  • edited July 2010
    See if your local auto parts store will loan you an OBDII code scanner. Read the code. Write it down. Then you can use the scanner to clear the code.

    Sounds like there's a problem that will just turn the light back on. Figure out what the code is trying to tell you.
  • edited July 2010
    If the light is on then there are codes stored. Try the auto parts stores as Goldwing suggested.

    Unless its not actually a "check engine" light - are you sure it isn't a service indicator light that is telling you to maybe change the oil? The owner's manual is the source for getting the meaning of any of the dashboard light messages.
  • edited July 2010
    If it is in fact the CEL and there really are no codes present is it possible the computer itself has gone out?
  • edited July 2010
    Yes..A CEL with no stored trouble codes points to a ECM (engine control computer) failure.

    As long as there are no drivability issues, the only reason to worry about this would be getting through an emissions test..
  • edited July 2010
    Or it could simply point to a problem with the data link connector or its wiring. I own a GM and have found its electrical connectors to be among the flimsiest and least reliable of any vehicle I've owned. The last time I needed to pull codes, in fact, my DLC was iffy & needed some jiggling.
  • edited July 2010
    Ah yes, the spirit of Joseph "the Prince of Darkness" Lucas does seem to live on in some American cars. Here's a link to some Lucas jokes. My favorite: "Why do the British drink warm beer?" Answer: "Lucas refrigerators"
  • edited July 2010
    Your local parts store can also sell you a perfectly OK basic code scanner for around $60 depending on whether they have one on sale or not. It'll work with any car made for the North American market since 1996 and probably with post 2010 vehicles for at least a few more years. It'll allow you to read and reset codes. It may be less trouble to do the readouts yourself than to drive around to mechanics and parts stores while you work out what is going on. Throw the scanner in the glove box after the problem is cured. Just remember to take it with you when you buy another car.

    I don't know enough about ECM programs to be sure. But given that they are computer programs, I'll bet that some of them are capable of checking stored codes, turning the CEL on based on the stored codes, then -- after monitoring the car, clearing the codes but forgetting to turn the CEL off. If your ECM has a bug like that, it could mean that some intermittent condition could give you a CEL on, no codes condition sometimes. You just need to catch the codes when they are present -- which they will be at times.
  • edited July 2010
    Thanks for all the suggestions. We did indeed take it to a parts store last night. He hooked in the scanner, no codes. He removed it, turned the car on, tried again, no codes. Maybe it is the "service engine soon" light, but I just had the oil and the air filter changed and I checked the gas cap as well. No drivability issues...yet. I'll have my husband check the DLC tonight.
  • edited July 2010
    vtcodger2, that site is hilarious along with the link to the Haynes comments site.
  • edited July 2010
    There is some sort of trick you need to do to turn off the light after the service is done. The trick is to find out how it is rest for your car.
This discussion has been closed.