2000 F150 OD light flashing

I have the 4.6L, 4x4 with tow pkg. The column shifter has the button on the end to engage or disengage OD. This light has now started flashing. When I push the button, nothing happens. It seems to be stuck in 3rd.An idea's?

I have the 4.6L, 4x4 with tow pkg. The column shifter has the button on the end to engage or disengage OD. This light has now started flashing. When I push the button, nothing happens. It seems to be stuck in 3rd.An idea's?

You really need to get it on a good transmission/engine capable scanner and see what is going on.
For a quick fast free check some auto parts places offer free code checks but are usually only OBD11 codes.
Just get the code and post back.
MT