abs module / Ecu enquiry

Hi anyone experienced in electrics , can i disconnect abs or ecu module plugs to check condition and wiring back to alternator , then re connect,without needing to re- boot system as dont have Vcds or similar. Currently trying to track down esp fault on dash + button on centre lit also comes on with-out fail after 10 mins stationary or rollin . Look forward to your reply.Chas .

Disconnect negative side of battery first.
This should be done on every and all work done!