Illumination of the Check Engine Light can be caused by a loose or worn gas cap.Google+
Car Problem Reports
Cadillac Escalade Check Engine Light Due to Gas Cap Issue
Cadillac Escalade Problem
Average Mileage: 97,404 mi (16,500 mi - 175,000 mi)
Visitor, 2004 Cadillac Escalade, 95,000 mi
Tighten gas cap message comes on every time I get gas. The cap is secure. Now my check engine symbol has come on.
Visitor, 2004 Cadillac Escalade, 125,000 mi
Check engine light comes on because the tighten gas cap light comes on. I replaced the gas cap and it still happens.
ENGINE LIGHT CONTINUES TO COME ON. WHEN DIAGNOSE THE SAME CODE APPAIR. APPROX EVERY 3000 MILES THE LIGHT SEEM TO COME BACK ON.
Visitor, 2004 Cadillac Escalade, 102,000 mi
Check engine light on. Several codes produced with Autozone scanner. Replaced with a new cap and took battery cable off to turn engine light off.
Visitor, 2004 Cadillac Escalade, 92,000 mi
Got a new gas cap from auto zone and had a mechanic shut off the code after diagnosing the issue.
Visitor, 2006 Cadillac Escalade, 75,000 mi
The gas cap warning light is on. I replaced the cas cap but I still get the light warning and the check engine is on.
Check Engine Light Due to Gas Cap Issue
I actually put a sandwich bag around my gas cap and then put it back and the check engine light went away.
Visitor, 2003 Cadillac Escalade, 175,000 mi
Check engine light on
Visitor, 1999 Cadillac Escalade
In normal operation the engine light came on. Went to AutoZone and they ran a diagnostic check and told me the gas cap was bad. I went to the dealer who did not hurt me to badly, replaced the gas cap which took all of two (2) minutes and drove the car. The dealer told me that the light would go off after 15 cycles (starting, driving, and cutting the car off). Seems like it took forever for the light to go off but it finally did. The car just turned 100k.
Visitor, 2005 Cadillac Escalade, 93,000 mi
tighten fuel cap warning goes on causing check engine light to illuminate