Phone Module (PHM) (2003-2005): Design: Handset

Fig 1: Identifying Handset

Courtesy of VOLVO CARS CORPORATION

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 cradle, all voice calls are hands free. The handset is activated when it is removed from the cradle. The cradle signal to the phone module (PHM) is controlled by a solenoid 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. The signal is 5 V when the handset is in use.

There are diagnostics for the handset.