Service Engine Soon light on

Hi. My husband has a 99 Pontiac Grand Am GT. The other day, he got gas and later in the day the Service Engine Soon light came on. He fiddled with the gas cap to make sure it was on tight, and now, 2 days later, the light is still on. We bought the car used with Toyota and they want to run a diagnostic test on it, which costs $82.00. I was told that if you reset the switch, the light should go off. If it comes on again a few miles later, to have it looked at. Problem is, Pontiac tells me there is no way to reset this switch. Can anyone offer me with a way to do this so I can possibly avoid paying the money for the test? The car runs fine. Thank you.

I'm not sure on this particularyear and model, but on some newer GM vehicles when the CE light comes on because of gas cap not being on right or tight, it takes a few cycles of the puter 'check' for light to go off when problem corrected. I think the check is run when it is started.

Yeah, the women at Pontiac told me it could take 3-4 days and another person told me a week. I would just love to reset it and see if it goes back on before taking it for a diagnostic test. It runs fine, but if there is something wrong, I do want to get it fixed. I just don't want to sdpend the money for them to tell me they just needed to reset the switch.

Someone (Toyota Manager)told me that with Pontiac, I could loosen the negative plug of the battery and leave it undone for 10 seconds. Plug it back in (reset my radio stations), but the light should be out. Anyone ever hear of this?

I have heard of the battery thing before, but I'm not sure if it works on newer technology. One possible in-exspensive way to check would be to take it to auto-zone (if you have one nearby), I believe they will check Code for free.

I have heard of the battery thing before, but I'm not sure if it works on newer technology. One possible in-exspensive way to check would be to take it to auto-zone (if you have one nearby), I believe they will check Code for free.


Forgive me for asking, what do you mean by they will "check Code" for free. What does check Code mean? will this reset it? we do have a couple AutoZones by us. Thanks.

It means they will hook up diagnostic tool to see what code is stored for CE light. If the code indicates problem with fuel evaporative system , it is most likely the gas cap. They do the check without charge (in hopes to sell parts ;) ). I don't know if they can (or will) reset the code. Good luck

And I assume the CE light is the same as Service Engine Soon (the light i think actually says all that).

Thanks for all your help. I am calling AutoZone now. :lol2:

Just talked to Autozone and they told me they would reset it for me for free too. Thanks a bunch!!

Hold that thought until you see if it works :)

Well, I figure if it doesn't, then I will pay the money to really have it looked at. I just don't want to pay for no reason.