[Richard L]

I think you may be confused with the function of the "B". B does not indicate a failsafe trip.

B comes on at the start of an injection event (when threshold is reached). It stays on about 100mS + FSDL, during this time the flow signal must be inside the window area. If it does, the 3-second failsafe will trip and drop boost.

B (100mS) + FSDL allows the flow signal to stabilise so the false alarm will be minimised.

If you cannot get the WL to trip, rotate the WL clockwise or decrease the FSDL.