Parking Brake Light Flashing

I've got a 91 S-10 4.3L V6 Automatic. The parking brake light keeps flashing whenever I'm driving. It is one long flash, then nine or ten short flashes. This pattern just keeps repeating.
Anyone know what this means?

Pop the hood and right by the master cylinder is a black box with 2 connectors. Unplug it and see if it comes back on. The "Brake" light is also you ABS warning light if you count the number of flashes between the 2 long ones including one long one I can tell you what the code is.

ie long short short short long ...would be a code 4

It has - long - 9 short - long -

Someone told me to disconnect the battery (which resets the codes?). It stopped the flashing, and hasn't come back on since. It rides and brakes fine.