pull the fuse on the main box the 7.5
(another answer)
The check engine light means that something in the engine electronics, such as a sensor, is not allowing the engine to run "closed loop". Ignoring this problem will mean that a) the vehicle will not pass the next smog inspection, if you live in a state like California, and b) you will likely get reduced gas mileage and possibly performance.
Take your car to a service station, or dealer, to hook up to the engine computer to ask what the problem is. It could be that you need new oxygen sensors, for example. You can do this yourself if you can get the right equipment to connect to the computer. Some places rent this gear. [Oh, I forgot to mention that some cars are designed to automatically turn this light on every 100,000 miles (or 50,000) just to get you to the dealership to have it turned off, for a small inspection fee, of course]
How do you reset check engine light for the 2009 Chevy trail blazer?
Random cylinder misfire
There are pages and pages of things that can cause a check engine light. You need to have it checked with a scantool. Then the code can be diagnosed and repaired.
Bulb may be blown or has been removed.
The check engine light is triggered by the Engine Control Module (ECM). The ECM receives information from many sensors and determines when to illuminate the check engine light.
It is important to know what the lights on the dashboard mean. To turn off the check engine light a person needs to repair the issues in the engine.
At key on it should come on for a couple second "bulb check".
You have a severe misfire. See related questions below.
To tell you to read the diagnostic codes.
The engine will develop a skip and the check engine light will illuminate. The code set in the ecm will direct you to which injector is bad.
Maybe you should service the engine soon. :P
Try disconnecting the battery for 10 minutes. May reset the light--if problem persists light will come back on