Network Communication

WARNING: This page is about a different car, the 2010 Mercury Mariner and 2010 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

The following audio system components communicate via the MS-CAN:

ACM
Navigation ACM
FDIM
FCIM
APIM
GPSM

There are numerous messages internal to the audio system. The functions of these messages include (but are not limited to):

Changing the audio source
Changing equalizer settings
Updating the FDIM display
Dialing phone numbers from the FCIM (if equipped with the SYNC system)

In addition, the following messages are utilized by the audio system in conjunction with systems outside of the audio system:

AUDIO SYSTEM MESSAGE REFERENCE CHART

Message	Transmitting Module	Receiving Module(s)	Function
Accessory Delay Status	Smart Junction Box (SJB)	ACM FCIM FDIM	When active, this signal allows the audio component to be operated after the vehicle is shut off.
eCall Notification	Restraints Control Module (RCM)	APIM	Provides the eCall status to the APIM . This message is also used to confirm that the APIM and RCM are both configured for the eCall feature.
eCall Status	APIM	RCM	Provides the eCall status to the RCM . This message is also used to confirm that the APIM and RCM are both configured for the eCall feature.
GPS Data	GPSM	APIM	Provides the vehicle location, speed, and heading to the APIM .
Battery % Available (hybrid)	Instrument Cluster (IC)	ACM	Indicates the approximate charge status of the high-voltage battery. This message only applies to vehicles with navigation.
Compass Display Status	IC	FDIM	Indicates the compass heading or mode (calibration, zone). This message only applies to vehicles without navigation.
Climate Control NavChassis Information Status	EATC	ACM	Indicates EATC settings as provided by the navigation ACM .
Engine Torque Commanded (hybrid)	IC	ACM	Indicates the power flow of the hybrid powertrain. This message only applies to vehicles with navigation.
English/Metric Display Mode	Instrument Cluster (IC)	ACM	Indicates whether English or metric units is currently selected.
FCIM Button State	FCIM	ACM APIM IC	Indicates when a button is pressed on the FCIM so the audio system can make the desired setting change.
Fuel Economy (hybrid)	IC	ACM	Indicates the approximate fuel economy. This message only applies to vehicles with navigation.
Ignition Switch Position	SJB	ACM FCIM FDIM	Indicates the ignition position to the audio system modules in order to control power management.
Illumination Dimmer Level	SJB	ACM FCIM FDIM	Controls the backlight intensity, based on the position of the dimmer switch.
MyKey(™)	IC	ACM	Provides the current MyKey(™) type to the ACM for use with the volume limiter and safety belt chime audio mute features.
Navigation Radio Rolling Wheel Count	IC	ACM	Provides for more accurate tracking of the vehicle position when the GPS signal is temporarily unavailable. This message only applies to vehicles with navigation.
Navigation Climate Control Status	ACM	EATC	Indicates climate control settings from the navigation ACM to the EATC .
Odometer Rolling Count	PCM	APIM	Provides the odometer reading to the APIM in order to initiate maintenance interval notifications.
Temperature Display Status	HVAC module	FDIM	Indicates certain climate control settings (such as temperature, fan speed, air distribution).
Transaxle Selector (PRNDL) Range	IC	ACM	For the navigation system, this signal is used for more accurate navigation tracking.
Vehicle Identification Number (VIN) Information	IC	ACM	Provides the VIN to verify the correct modules are installed.
Vehicle Speed	IC	ACM	Used by the ACM for the speed-compensated volume function.
Volume Cutback	IC	ACM	When this signal is active, the speaker output is reduced to allow the parking aid tone to be more easily heard. The IC gateways the message from the Parking Aid Module (PAM).