Disconnect Battery then turn on key to crank position hold in crank position for 1 minute then remove key and reconnect battery,
NEW ANSWER: The above answer is all wrong. It requires an engine scanner to reset the check engine light. But FIRST you must FIX the problem that made it come on in the first place are it will just come on again.
Check the brake light switch on the brake pedal
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.
How do you reset check engine light for the 2009 Chevy trail blazer?
You can either bring it in to a Chevy dealer or use a programmer/tuner to reset the check engine light.
If the check engine light is blinking that means an engine cylinder misfire has been detected
I was told by a co-woker that if you disconnect the negative battery cable for about 20 minutes or so that will reset the service engine light.
Check
The check engine light (service engine soon) comes on and stays on when a problem is detected by the self diagnosis system of your vehicle.
It requires an engine scanner to do that.
No, only a problem that effects emissions will set the check engine light.
A flashing check engine light is an indication of a misfire.
That REQUIRES an ENGINE SCANNER to do that.