My furnace fault code light flashes three times the pause and flashes three times again and repeats. What is wrong?

Furnace fault code flashes three time and pause then flashes three times. Just repeating itself. What is it telling me?

Look on the inside of the blower access door for a legend of the blink/flash code. It will tell you there.

Also try recycling the power.

I am missing the legend. Any idea where I can find one? Mine is also blinking 3 times