CAUTION! If for any reason you do need to use a jumper on MR Eng. mode, if at all possible, you should never jump both the cabin and hall door contacts simultaneously. That SHOULD ONLY be done as a LAST RESORT. No DLM system (if installed) is 100% failsafe. Only jump the contact of the applicable door that is not capable of closing. That way if DLM is not enable or fails, the lift won't move with doors open on normal service.

Don't forget about the Suzzane Hart story in NYC. Safety first!