Illumination of the Check Engine Light can be caused by a loose or worn gas cap.Google+
Car Problem Reports
Cadillac CTS Check Engine Light Due to Gas Cap Issue
Cadillac CTS Problem
Average Mileage: 78,138 mi (11,872 mi - 180,000 mi)
Visitor, 2006 Cadillac CTS, 38,618 mi
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.
Visitor, 2003 Cadillac CTS, 64,000 mi
Ive been having the engine light stay on now.........changed the gas cap.. still on.... 2003 cts v6
Visitor, 2003 Cadillac CTS, 119,000 mi
same problem with my car check engine light due to gas cap
Visitor, 2007 Cadillac CTS
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.
Visitor, 2003 Cadillac CTS, 92,000 mi
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!
Visitor, 2011 Cadillac CTS, 32,000 mi
c-1 coil gone already ??
Visitor, 2003 Cadillac CTS, 85,000 mi
I replaced the gas Cap and corrected the problem.
Visitor, 2003 Cadillac CTS, 146,000 mi
On dash said check gas cap, took it off, put it back on, corrected problem.
Visitor, 2009 Cadillac CTS, 56,000 mi
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.
Visitor, 2006 Cadillac CTS, 70,000 mi
Engine light on due to gas cape