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Pete, Buick Technician
Category: Buick
Satisfied Customers: 27634
Experience:  17 years Buick Technician experience and training.
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Buick LaCrosse CXL engine check light on

Resolved Question:

engine check light on
Submitted: 6 years ago.
Category: Buick
Expert:  Pete replied 6 years ago.
Hello,I will be glad to try and assist you with this,Welcome to Just Answer.


If your gas cap was loose most likely this is the reason the check engine light came on.The evap emissions has set a small or large evap leak code due to the cap being loose.

Now that you have tightened the cap you can either continue to drive the vehicle up to two or more weeks until the code clears itself out due to the computer running the evap test and seeing everything is o.k.,this usually takes 40 ignition cycles on and the computer to run its test 40 times,so this can take some time.

Or you can have the code cleared with a scan tool or code reader to turn this light off.Any shop or dealer can do this for you and I have also heard of some parts stores doing this for free in some places as well.

But the light will stay on either until it is turned off with a scan tool or code reader or the vehicle has ran and passed the test that set the code 40 consecutive times in a row.

Let me know if you need anything else,click accept if you feel satisfied with your answer as this is how I get credited for my time,Thanks Pete!
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