To find out why its on you'll need to either take it to a dealership or run a tuner on it and run a diagnostic check on the truck.
I have a 2006 Chevrolet C4500 Duramax Diesel and I would like to know how to turn off or reset the check engine light on the truck.
picture of engine
Why? Just reset it.
Duramax performance does not exist as a product, however Duramax is a diesel engine used primarily for light and medium duty trucks. The engine is produced by DMAX.
That requires an OBDII engine scanner.
To reset the "Service Engine Soon" light on a 1992 Chevrolet Astro, you can disconnect the battery for about 15 minutes. This will clear the engine codes and reset the light. Alternatively, you can use an OBD-I scanner (if available) to clear the codes. After resetting, ensure that any underlying issues are addressed to prevent the light from coming back on.
Have vehicle scanned to determine the problem and have codes cleared
There are pages of things that can turn the light on. You need to have it checked for codes. See related questions below.
If you have another light that says Check Engine, then the Service Engine Soon light means to change the oil/filter or perform some other maintenance item as listed in your owner's manual. You will see the other light when you turn on the ignition. If however there is no Check Engine light, this light means there is a problem with the emissions system.
The service engine light is the same thing as a check engine light.
You can either bring it in to a Chevy dealer or use a programmer/tuner to reset the check engine light.
The service engine soon light flashes when the computer senses a fault and sets a diagnostic code. Most auto parts stores will read this code for free and tell you what may be causing the problem.