Phone Module (PHM) (2001-2007): Design: Handset

Fig 1: Identifying Handset

Courtesy of VOLVO CARS OF NORTH AMERICA.

The handset is directly connected to the phone module (PHM). The handset is in the center console.

The phone module (PHM) determines whether to connect the call using hands free or the handset, depending on the signal from the cradle. When the handset is in the holder, all voice calls are handsfree. The handset is activated when it is removed from the holder. The cradle signal to the phone module (PHM) is controlled by a magnetic switch in the handset. The switch is closed by a magnet in the cradle. When the handset is in the cradle, the cradle signal to the phone module (PHM) is 0 V. When the handset is in use the signal is 5 V.

There are diagnostics for the handset.