There are no guard door controls in the cabs, the only door control buttons are on the drivers desk, which are not in a suitable position for use by the guard. They were only built with door controls in the saloon, which will partly be because of Northern's policy over the years of having guards not use cabs to operate doors (plus the whole DOO thing etc). When the 319s transferred to Northern, the door controls in the cab were disabled and saloon controls fitted. Also on Class 170s, guards are only allowed to use the saloon controls, cab controls can only be used with permission from control.