Speed board error right?
Something common to both up and down directions, terminal and intermediate landings, and no other faults.
The "100" part of the fault gets me. It's like the controller isn't seeing something right at the get go. Does it slowdown normal or at reduced speed?
Auxiliary contacts on M?
Bad contacts on a relay in the speed box? Those are bifurcated contacts, not just the run of the mill 4 pole relays.
Flakey hatch switch?