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My 2005 cadillac deville service engine soon light comes on i had it checked and no problems except check my gas cap light comes on Please advise. Thank you.

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I have got this code before and it just be lose gas cap.....but have also had to replace the cap on a few of them .....the vent hole in it gets cloged....hope it helps

Posted on Nov 16, 2010


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1 Answer

Gas cap service engine soon light comes and stays on?

Sorry mate, I dont know what this Gas cap is, could be the fuel filler cap, could be the car runs on LPG and it is a cap on the Gas charge line.

Sep 05, 2014 | 1999 Cadillac DeVille

1 Answer

P0440 indicates the failure of the EVAP system to develop proper vacuum. If you got
and replaced a proper good quality gas cap, you have corrected the most common cause.
However, in fully searching the causes of this code ( ) (pardon the generic GM info, but will apply for you)-----you will find there are 5 other causes of the vacuum failure, which are independent of the gas cap. Your good local mechanic can sort those out; I would save your gas cap
receipt if you were advised to buy one not needed. As you probably know, your
State emission test facility checks your gas cap----so that is another way to find that specific portion of this answer,
(for their fee).
P0300 is a generic misfire code. For this, a specific Cadillac forum may be most
helpful = 2001 Deville intermittent service engine soon light code P0300
co-logo-100x100.png 2001 Deville intermittent service engine soon light code... I recently bought this car from an owner who took decent care of it but a week after i bought it, the service engine light appeared. After a few View on www.cadillacforums... Preview by Yahoo You will see that this generic code is perhaps more serious, costly, and harder
to track down than the P0440. You will also discover that P0301 is cylinder 1 misfire, P0302 is cylinder 2, and etc, etc. If you get a good diagnostic, they will generally
be able to localize the problem fairly specifically---and get a more specific fix. The person who reported this code was unhappy because he was given several ($$) fixes,
before he got one that erased the code, and was a solution. (Be forewarned ----A generic misfire can have umpteen issues--or one! !; use your own local preferred method for solving this with a mechanic who gives you good service, and stands behind what they do.)
2001 Deville intermittent service engine soon light code P0300

Jun 04, 2014 | 2001 Cadillac DeVille

1 Answer

Service engine light stays changed gas cap done smoke test replaced oxygen sensor

Code 449 is for a defective vent valve solenoid. The engine computer can not open or close the valve or can not tell if the valve is operating.
The valve/solenoid would need to be tested and you will probably need a shop manual to get the testing procedure.

Mar 06, 2014 | Cadillac DeVille Cars & Trucks

1 Answer

The service engine soon light came on what does that mean that s happen

Some problems are intermittent. If the engine check light is now off (except momentarily when you turn on the ignition and start) and staying off, just drive on.

Dec 03, 2013 | 2001 Cadillac DeVille DTS

1 Answer

I disconnected and re-connected Battery on 1997 Deville northstar. Service engine soon light came on, will it go off in the 60 miles when computer resets?

If the check engine light comes on, then the coputer has detected a problem. Disconnecting the battery for about 15 minutes will "reset' the computer. Howwever if the problem still exsists, the light will come back on. It could be a simple as a loose gas cap or something more complex. The only way to determine what the problem is, is to retrieve the code(s). You will need an OBD II code reader. In some states your local auto parts store will do this for you.

Aug 11, 2011 | 1997 Cadillac DeVille

1 Answer

Check engine light came on in a 2005 DHS? what are the common problems to cause this to come on?

"Check engine" light can come on for any number of reasons. A loose gas cap can make it come on or a bad O2 sensor. No way to say what the most common reason is over the internet. Depending on what state you live in, AutoZone will retrieve the code(s) for you for free. You need to take it in and have it diagnosed, if it is the O2 sensor and it isn't fixed soon it may cause the catalytic convertor to go bad and they aren't cheap!!

Dec 23, 2010 | 2001 Cadillac DeVille

1 Answer

I have a 2001 Cadillac DeVille DHS, 144K miles, runs pretty smooth except some warnings: 1. Check Gas Cap warning is always there even after I tightened the gas cap, 2. Service Engine Soon light is always...

Yes, first try securing it tighter. This means until you hear it making noise. Go to advance or autozone and have them reset the code. If it still turns the SES light on, replace the cap. My 2001 DTS did the same thing at 144K. You may be on the same track I am on. So far I replaced that, the EGR solenoid (get the Delphi brand) and now it looks like I have to replace my EGR vent. During this I also had to replace my fuel pump. Fortunately on this model it's easy to get to through the trunk. I ended up having to splice in a new connector. They don't come with the old one any more. Good luck.

Feb 19, 2010 | 2001 Cadillac DeVille

2 Answers

Service soon light came on on my 86 cadillac deville so i was wondering is that the same thing as a check engine light or different?

"service soon" is a reminder that it needs regular maintenance, and usually the dealer has a tool to reset that light on the dashboard, which can be expensive to buy.

If you do all the maint yourself, and you know that all the fluids have been replaced or capped off, you could cover the light with a piece of black electrical tape, then go on with your life.

May 24, 2009 | 1986 Cadillac DeVille

2 Answers

2003 Cadillac Deville a check gas cap error appears with svc engi

put a new gas cap, those system are pres. even if
the cap look ok it maby leaking replace with a new
one it should solve your prob.
eng.ligh come on because of the gas cap

Apr 09, 2009 | 2005 Cadillac Seville

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