Check Engine Light Due to Gas Cap Issue on Cadillac CTS

Problem Description and Possible Solution

Illumination of the Check Engine Light can be caused by a loose or worn gas cap.

Problem Data
RepairPal Verified
Average mileage: 85,062 (11,872–207,600)
10 model years affected: 2003, 2004, 2005, 2006, more2007, 2008, 2009, 2010, 2011, 2012
69 people reported this problem
Viewing 1 - 20 of 22 comments
Ive been having the engine light stay on now.........changed the gas cap.. still on.... 2003 cts v6
at 48000 miles the check engine light has come on 3times the the car dealer replaced a sensor to the gas tank and it came back on. The GM dealer said it was the wire to the sensor. A week later it came back on. They spent 4 hours trying to figure it out. They reset it. Now at 54000 miles it is on again. I am thinking somebody at on star is putting the light on. I had simular problems with my 97 catera oillight. And now my warranty is done. The front passanger shock is making noise. The auto trac and auto stablization is out of control.
126000 miles when problem started
Engine light came on due to gas cap vacuum leak
Ingine light came on and I had it checked for free at NAPA and was told that probably the gas cap not sealing correctly and to replace this first...... Replaced the cap at a cost of around $8 and that fixed that problem... By the way NAPA had the replacement cap right there in their store... No service charge just the purchase of the new gas cap... Problem fixed and light off!
Cap was loose and caused check engine light. When tested error read as some kind of leak. But, all was needed was to tighten the gas cap and have the error message removed.
Light came on and was diagnosed with leak in emissions system. Purge valve was replaced. 2 days later, light came on again. Gas cap was replaced and exactly 2 days later light came on again.
Too lazy to buy another gas cap, doesn't seem to effect much, just an annoying light.
same problem with my car check engine light due to gas cap
Check engine light comes on due to gas cap not sealing.
engine light light up due to Gas Cap Issue. I replaced it...
Engine light on due to gas cape
c-1 coil gone already ??
I replaced the gas Cap and corrected the problem.
I am in the process of purchasing this year Cadillac and the dealer is saying he will get it smog tested and the check engine light came on now I know why it's taking so long hopefully it will get fixed and I won't have anymore issues
Traded this car to my sister and noted engine light on shortly after she got it last spring.
Also the high beam light bulb wasn't working. Cost her $500 to get it replaced (fixed)
So much for trying to give her a decent car.
Check engine light came on took to dealership and they told me the gas cap was loose
This may be a cap issue, but it also may be # 3 clyinder. It will be expensive to find out
replace gas cap
Engine light came on due to gas cap.