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Home >> Volvo >> 2007 >> V70 R, Automatic >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Alarm System, Control Modules, Engine Management Systems - Design And Function >> Accessory Electronic Module (AEM) (2001-2007) >> System overview >> Signals
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System overview: Signals

The chart below summarizes the input and output signals to and from the accessory electronic module (AEM) (4/78). The signal types are divided into directly connected signals and Controller area network (CAN) communication. The following illustration 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 reverse warning system control module transmits a buzzer signal (mute signal)
  • Remote start module (mini call, remote control) for remote starting the parking heater (start/stop signal)
  • The tele-mute signal from after market hands free units to the carphone to mute the volume on the audio module (AUM) (AUD) or after market radio unit.
Directly connected: 
  • Four signals for RTI (road traffic information) for Japan:
    • Speed
    • Reverse gear indication
    • Lighting signal
    • X-supply to the relay.
  • Parking assistance module (PAM) (voltage and ground terminal)
  • Start for the parking heater consisting of +12V to the relay for the electrical parking heater
  • External alarm unit (trigger signal/power supply)
  • Signal for integrating an after market radio unit (tele-mute signal, speed signal, rheostat signal and controlled power supply to the external antenna amplifier)
  • Tele-mute signal from an after market handsfree unit to an after market radio unit
  • Mini call unit for remote start, supply and ground terminal connection.
Via Controller Area Network (CAN):  Via Controller Area Network (CAN): 
  • Central electronic module (CEM) (4/56):
    • Start and stop signal, to control the relay for the electrical parking heater
    • Reverse gear indication to start the reverse warning system
    • Reverse gear indication, for the RTI (road traffic information) system (Japan)
    • Vehicle speed signal, used by after market radio units and the traffic information system, RTI for Japan
    • Alarm status, used by the accessory electronic module (AEM) controlled external alarm
    • Light position, indicates parking lamps, low and full beam. Used by RTI (road traffic information) for Japan for the background lighting of the navigation display
    • Indication to not start the reverse warning system when a trailer is connected. Activated by switching on the turn signal lamps.
  • Audio module (AUM) (16/1):
    • Indicates the brightness of the background lighting.
  • Central electronic module (CEM) (4/56):
    • Remote start to activate the parking heater.
  • Audio module (AUM) (16/1):
    • Tele-mute signal
    • Reverse warning signal.
Fig 1: AEM Flow Chart
GLL108069Courtesy of VOLVO CARS OF NORTH AMERICA.