[8D]This morning, the Check Gas Cap and Engine light came on at the same time on my 03 CTS.Cleared the Cap but the Engine light stayed on.Called my dealer. He said he has seen problem Caps, not sealing right cause this!The cap was loose . I know I did it tight at last fill up.Question. can I clear this from the memory by disconnecting the battery and re-connecting?Thanks for any help.

 

HOW TO "ENTER" DIAGNOSTIC MODE
To enter diagnostic mode, proceed as follows:
[ol][*]Turn ignition "ON." Engine can be either OFF or RUNNING.[*]Depress the "ON/OFF" button and the "UP ARROW" end of the info button on the driver information center simultaneously for a few seconds. [/ol]
All the dashboard lights will illuminate, including the segments of the DIC display. You are then presented with text. You can cycle through different questions using the UP and DOWN arrows on the info button. and clear codes as desired.

 

K.C. thanks for reply. what do u think about his loose gas cap explanation? When I removed and replaced the cap tight, the engine icon stayed lit.So, disconnecting the battery will not clear this from the memory? Thanks again.

 

I have experience with my GMC and a loosening gas cap. I will admit that I disconnect the computer lead to reset it and clear the SES light. That would seem to be equivilent to disconnecting the bat. I don't know why I just don't get a new cap.[sm=bangbang.gif]

Once the light comes on it won't necessarily go off right away once the problem is corrected. On my GMC it comes and goes depending on who filled it up and how tightly they cranked it. Some times it will go out two blocks after being filled up, some times it won't. I believe the owners manuals used to say you need to give it one or two fill ups to correct itself.

 

Hey I have a question, when you say depress the "on & off" button, what on and off button are you talking about? and the A/C unit???
...Medieval_Cadi...

 

Could be a faulty cap, not that you didn't screw it on tightly. Happened with my vette, had to get a new cap. The car was only 2 months old at the time.