Network Communication
WARNING: This page is about a different car, the 2009 Mercury Milan, 2009 Lincoln MKZ, and 2009 Ford Fusion. 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:
- Audio control module (ACM)
- Navigation ACM
- Satellite digital audio receiver system (SDARS) module
- Audio digital signal processing (DSP) module
- Accessory protocol interface module (APIM)
The following messages are utilized by the audio system:
AUDIO SYSTEM
| Message | Transmitting Module | Receiving Module(s) | Audio System Function |
|---|---|---|---|
| Ignition Switch Position | Instrument cluster (IC) | ACM DSP module |
Indicates ignition switch position for power-up/shut-down. |
| Illumination Dimmer Level | Smart junction box (SJB) | ACM | Controls the backlight intensity, based on the position of the dimmer switch. |
| Transmission Selector (PRNDL) Range | IC | ACM | For the navigation system, this signal is used for more accurate navigation tracking. |
| Volume Cutback | Parking aid module (PAM) | ACM | When this signal is active, the speaker output is reduced to allow the parking aid tone to be more easily heard. |
| Accessory Delay Status | SJB | ACM | When active, this signal allows the audio component to be operated after the vehicle is shut off. |
| Vehicle Speed | IC | ACM DSP module |
Used by the ACM (or DSP module) for the speed-compensated volume function. |
| Navigation Radio Rolling Wheel Count | IC | ACM | For the navigation system, this signal is used to more accurately track vehicle position when the GPS signal is temporarily unavailable. |