Design

Design

Car phone box




The phone box communicates with the phone module (PHM) via a communication bus installed on the right-hand side of the car. It transfers audio signals, voltage and messages for communication. The phone box contains a GSM unit and a SIM card holder.
There are diagnostics for the phone box.

Car phone antenna




The car-phone antenna is mounted on the windshield (in front of the rear view mirror). The car-phone antenna is directly connected to the phone box via a cable with a quick-release connector.
There are not diagnostics for the car-phone antenna.

Handset




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 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 hands-free equipment works if there is a fault with the handset.
There are diagnostics for the handset.

Hands-free equipment




The hands-free equipment consists of a microphone and a speaker.
The microphone is in the rear view mirror and is directly connected to the phone box. For aftermarket car phones, the microphone is a swan neck type, mounted in the head restraint on the driver's seat.
The loudspeaker is in the head restraint on the driver's seat and is directly connected to the phone module (PHM).
Only the handset works if there is a fault with the hands-free equipment.
There are diagnostics for the microphone and speaker.