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System Overview: Signals

The table below summarizes the input signals to and output signals from the accessory electronic module (AEM) (4/78).

The signal types are divided into directly connected signals and Controller area network (CAN) communication. The illustration below displays the same information with the Volvo component designations.

NOTE:

The signals are only available for installed accessories.

Input signals Output signals
Directly connected: 
  • The telemute signal from after market hands free unit to the carphone to mute the volume on the sound system.
Directly connected: 
  • Start for the parking heater consisting of +12 V to the relay for the electrical parking heater
  • External alarm unit (status signals).
Via Controller Area Network (CAN) communication:  Via Controller Area Network (CAN) communication: 
Central electronic module (CEM)  (4/56):
  • Start and stop signal, to control the relay for the electrical parking heater
  • Alarm status, door status, key status. Used by the accessory electronic module (AEM) to control the external alarm.

Steering wheel module (SWM)  (3/254):
  • Manual start and stop signal, to control the relay for the electrical parking heater. Via central electronic module (CEM).
Infotainment control module (ICM)  (16/1):
  • Telemute signal via infotainment control module (ICM) via the MOST network to the audio module (AUD).

Central electronic module (CEM)  (4/56):
  • Start and stop signal, to control the relay for the electrical parking heater
  • Start and stop signal, to control the combustion preheater module (CPM) (for fuel driven parking heaters).
Fig 1: Identifying AEM & Components
GLL117542Courtesy of VOLVO CARS CORPORATION