reet bandit. . .yer ignition key has a transponder ,this sets the code for engine isolation, yer alarm [imoberliser] is worked off ya doors [central locking] all signals go to a ecu , if using key it says ok all doors are shut un windows up engine orft un bonnet shut[lock] any low life tryin ta open doors or bonnet [alarm go's] . . .ok now the fob, press alarm ont fob un ecu sis all doors un windows are shut so this time dead lock all doors and set the interior movement detector [ no good for things that move inside cab] if low life decides ta smash ya windows [alarm go's]it also incorperates a movement detection,[car jacking] its a good system once set up proper, hope this helps. . . . . . .