Check lamp indicator is on

I need some help.
Few days ago, my Matrix shows the "Check Lamp Indicator" or "Malfunction indicator lamp" light out of the blue. It just suddenly shows up.
I don't feel any different about the car after this light turn on.

The light is located in the Speedometer and the those terms above I got from the owner manual.
The owner manual says "take vehicle to toyota dealer", I have not done that yet!
So I check all the lights that I can check as the term indicate "malfunction indicator lamp". But so far all lights are still working.
I wonder anyone had this problem and what do you do to fix it?

Thank you

It is commonly refered to as a "Check engine Light" it does need to go to the dealership for diagnosis. It could be something as simple as the gas cap being loose, or as major as the timing jumped.
good luck