That's telling you there is some type of problem.... On the later trannys there is a self diagnosis system, I think the early EFI/Auto trucks had it, but my FSM shows plugs that are probably different..... The steps are, turn thekey and O/D on (do not start truck) connect the "DG" connector to a chasis ground. (On my 89 the DG con. comes out of the wireharness on the drivers side of the engine bay.....)
The O/D light will flash out the codes like the check engine light for other troubles....
Maybe someone with an 85 FSM can chime in....
I hope that helps some.
'85 4Runner "Green Bastard" Ugly, but modified tastefully.
I have an 85 fsm and it says I should have a a43d tranny which I dont(a340h),tranny seems to work fine but the light will come on for about five minutes and then shut off.There should be a diagnostic connector some where(has to be if the light is flashing,must be a code)my haynes manual says the wire should be yellow/white,there is a yellw/blue wire with connector near efi diag. connector