Flashing OD light

This is a new one on me, My wife's 96 CVPI OD light started flashing a few days ago. It doesn't effect the switching on/off of the OD, but just flashes for about 30 seconds and stops, I am trying to determin if it is being set off when I hit a bump in the road. Anybody had they same problem or know what it means?

It means the EEC has detected a problem with the transmission, or the control circuits. The most frequent cause is overheated ATF. Have the codes read, and it will give some direction to the search for answers.

Should I be able to read them with a standard, ODB II from snap-on or will it need to be with a Ford code reader?

Virtually any scan tool that is OBD-II should work.