System Overview

Accessory Electronic Module (AEM)

System overview

Control module





The function of the accessory electronic module (AEM) is to allow certain accessories to exchange information with the controller area network (CAN) of the vehicle. The control module functions as an interface between accessories, which are not prepared for Controller area network (CAN) communication, and the Control area network (CAN) of the vehicle and its functions. This exchange of information means that accessories can be installed with greater functionality and higher quality.
The accessory electronic module (AEM) manages the following functions:
- relay for the electrical engine block heater
- outputs for external after-market alarms
- tele-mute for non-integrated carphones.

The functions managed by the accessory electronic module (AEM) may vary between different car models.

The accessory electronic module (AEM) is an accessory and is only available for order and installation as an after market item.

Adapter wiring is required when installing accessory electronic module (AEM). The control module is installed in the cargo compartment of the vehicles behind the side panel at the right-hand wheel arch.
After installation the accessory electronic module (AEM) is configured using software. Configuration is carried out via VIDA.

The control module communicates with directly connected components, and via a Controller area network (CAN).

The control module checks activations and input and output signals via an integrated diagnostic system. A diagnostic trouble code (DTC) is stored if the control module detects a fault. Any diagnostic trouble codes (DTCs) and stored in the control module memory and information can be read out using VIDA.

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: Directly connected:
- The telemute signal - Start for the parking heater
from after market hands free consisting of +12 V to the relay
unit to the carphone to mute for the electrical parking heater
the volume on the sound system. - External alarm unit (status signals).

Via Controller Area Network Via Controller Area Network
(CAN) communication: (CAN) communication:
Central electronic module : Infotainment control module
(CEM) (4/56) (ICM) (16/1):
- Start and stop signal, - Telemute signal via infotainment
to control the relay for the control module (ICM) via the MOST
electrical parking heater network to the audio module (AUD).
- Alarm status, door
status, key status. Used by
the accessory electronic
module (AEM) to control
the external alarm. Central electronic module (CEM) (4/56):

Steering wheel module - Start and stop signal, to control
(SWM) (3/254): the relay for the
electrical parking heater
- Manual start and - Start and stop signal,
stop signal, to control the to control the combustion
relay for the electrical preheater module (CPM)
parking heater. Via central (for fuel driven parking heaters).
electronic module (CEM).