Phone Module (PHM) (1999-2000): Design: Handset
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2006 Volvo S80, 2005 Volvo S80, 2004 Volvo S80, 2003 Volvo S80, and 2002 Volvo S80. However, it is still accessible from the selected car via links, so may be relevant.
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 handsfree. The handset is activated when it is removed from the cradle. 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.
Only the handsfree equipment works if there is a fault with the handset.
There are diagnostics for the handset.