Principles of Operation

Information and Entertainment System

Principles of Operation

Audio Front Control Module (ACM)

The Audio Front Control Module (ACM) can be operated with the ignition in RUN or ACC. The accessory delay feature allows the audio system to be operated for a preset period of time after the ignition is turned off and a front door has not been opened. The ACM (Audio Front Control Module) sends AC voltage audio signals to the speakers or to the amplifier, depending on vehicle configuration. The ACM (Audio Front Control Module) can produce its own DTCs, which can be communicated to the scan tool through the Medium Speed Controller Area Network (MS-CAN).

Audio Front Control Module (ACM) Illumination

The base (AM/FM) ACM (Audio Front Control Module) has a hardwired illumination circuit from the Body Control Module (BCM). For all other ACMs (Audio Control Modules), the illumination signal is received via the MS-CAN (Medium Speed Controller Area Network).

Satellite Audio

The satellite audio system consists of a satellite radio antenna, and a satellite radio antenna cable. All vehicles with navigation have the SDARS (Satellite Digital Audio Receiver System) module built into the ACM (Audio Front Control Module). The satellite radio antenna receives digital audio signals and sends them to the ACM (Audio Front Control Module).

Subwoofer

The premium audio subwoofer and amplifier are integral. The function of the enable/clip detection circuit is to turn the amplifier on and to indicate to the ACM (Audio Front Control Module) when the subwoofer output distortion signal reaches a damaging level. The ACM (Audio Front Control Module) then clips the audio output signal to prevent damage to the subwoofer.

Navigation System

The navigation system guides the user to a pre-entered destination. No navigation map DVD is needed, as the map guidance information is stored in the ACM (Audio Front Control Module). The ACM (Audio Front Control Module) calculates route information based on Global Positioning System (GPS) data. The GPS (Global Positioning System) antenna tracks several satellites simultaneously. The ACM (Audio Front Control Module) also uses vehicle speed and transmission gear selected signals received through the MS-CAN (Medium Speed Controller Area Network) to detect vehicle speed and direction, resulting in more accurate navigation tracking.

The navigation display is part of the ACM (Audio Front Control Module). Either the touchscreen or the buttons on the ACM (Audio Front Control Module) can be used to interact with the navigation system.

The compass heading is derived from the GPS (Global Positioning System) antenna signal. There are no serviceable parts for the compass.

A voice recognition system allows the user to interface with the system without using the touchscreen. A microphone located in the headliner provides a direct input to the ACM (Audio Front Control Module). The microphone is shared with the SYNC(R) system.

Jukebox Feature

The navigation ACM (Audio Front Control Module) contains a 10 gigabyte on-board hard drive that is capable of storing music ripped (recorded) from a music disc. The music can be loaded into the jukebox by inserting a disc (in the correct format) and following the on-screen instructions to load the music into the ACM (Audio Front Control Module). The jukebox cannot rip MP3 discs.

SYNC(R) System

The SYNC(R) system allows interaction with several types of customer devices, including mobile phones and media devices. The system consists of the Accessory Protocol Interface Module (APIM), a microphone (located in the headliner), the Universal Serial Bus (USB) cable and port and the audio input jack. The APIM (Accessory Protocol Interface Module) contains an on-board Bluetooth(R) chipset, which enables certain wireless devices to interact with the system.

The APIM (Accessory Protocol Interface Module) consists of a Consumer Interface Processor (CIP) and a Vehicle Interface Processor (VIP). The modules are not replaceable individually, but can be flashed independently, if required.

The CIP (Consumer Interface Processor) interfaces with all of the inputs to the APIM (Accessory Protocol Interface Module). It contains an analog-to-digital-to-analog converter, as well as the Bluetooth(R) chipset. Any consumer-available application upgrades that are available are loaded directly to the CIP (Consumer Interface Processor) through the USB (Universal Serial Bus) port.

The VIP (Vehicle Interface Processor) provides an interface between the CIP (Consumer Interface Processor) and the vehicle. Its main functions are controlling the APIM (Accessory Protocol Interface Module) power management and translating both inbound and outbound signals over the Controller Area Network (CAN). In addition, the VIP (Vehicle Interface Processor) interrogates the modules on the network to retrieve any DTCs when a vehicle health report is requested.

The APIM (Accessory Protocol Interface Module) can receive inputs from the following audio sources:

- USB (Universal Serial Bus) port

- Audio input jack

- Bluetooth(R)

The USB (Universal Serial Bus) port can be used for connecting a media device (such as an iPod(R)) with the device's available cable or for directly plugging in a portable mass storage device (such as a thumb drive). When playing media files stored on a mass storage device, the SYNC(R) system only plays files that do not have Digital Rights Management (DRM) protection. The USB (Universal Serial Bus) port can also be used for uploading vehicle application upgrades.

The USB (Universal Serial Bus) port is powered by the APIM (Accessory Protocol Interface Module), so no external power source is needed to power a device plugged into the USB (Universal Serial Bus) port if the device supports this feature.

The audio input jack can be used for connecting a media device (such as an iPod(R)) utilizing a 1/8-inch audio jack. When a device is connected through the audio input jack, only the speaker volume can be controlled by the ACM (Audio Front Control Module). All other functions (such as seek, fast forward and pause) must be carried out on the device itself.

The Bluetooth(R) interface can accommodate both Bluetooth(R)-enabled mobile phones and Bluetooth(R)-enabled media devices. Any Bluetooth(R) device used with the SYNC(R) system must first be paired with the system before it is operational.

Bluetooth(R) is a secure, short-range radio frequency that allows devices to communicate wirelessly through radio waves. The operating range of a Bluetooth(R) signal is a maximum of 32 feet.

Only one Bluetooth(R) phone and one Bluetooth(R) media device can be connected to the system at a time. If an additional device of either type is paired with the system and made active, the APIM (Accessory Protocol Interface Module) disconnects any active connection and establishes a connection with the new device.

It is important to understand that not all mobile phones have the same level of features when interacting with the SYNC(R) system. For a list of compatible phones, refer to SyncMyRide web site.

In addition to audio information, metadata may also be sent to the APIM (Accessory Protocol Interface Module) from a device plugged into the USB (Universal Serial Bus) port. Metadata consists of such information as artist, album title, song title and genre. The APIM (Accessory Protocol Interface Module) uses the metadata to create indexes that can be used to sort for particular music, based on customer preference. Not all USB (Universal Serial Bus) devices can send metadata to the APIM (Accessory Protocol Interface Module) ; also, no metadata is transferred when a device is connected through the audio input jack. When a new media device is connected to the SYNC(R) system, the APIM (Accessory Protocol Interface Module) automatically indexes the information. Depending on the amount of data on the device this may take up to several minutes and is considered normal operation. When a device that was previously connected to the SYNC(R) system is reconnected, the APIM (Accessory Protocol Interface Module) updates the index (rather than creating a new one), reducing the amount of time needed to index the device.

The APIM (Accessory Protocol Interface Module) receives both stereo and mono sound inputs and can also transmit both stereo and mono sound. The mono function receives the microphone input. It also sends sound to the ACM (Audio Front Control Module) for voice prompts, the Text-To-Speech (TTS) feature, ringtones and any audio received through a connected mobile phone. The TTS (Text-To-Speech) feature speaks information so that it does not have to be read from the display.

The APIM (Accessory Protocol Interface Module) communicates on the MS-CAN (Medium Speed Controller Area Network) and High Speed Controller Area Network (HS-CAN). Communication with the scan tool is established through the HS-CAN (High Speed Controller Area Network).

Global Positioning System Module (GPSM)

For vehicles equipped with SYNC(R) but not navigation, the Global Positioning System Module (GPSM) provides vehicle location for real-time traffic reports and re-routing, and for identifying vehicle location in the event of a collision. The vehicle location information is broadcast to the APIM (Accessory Protocol Interface Module) over the MS-CAN (Medium Speed Controller Area Network).

Voice Recognition For Vehicles With Navigation And The SYNC(R) System

When the audio system enters voice recognition mode, the ACM (Audio Front Control Module) initially controls the voice recognition feature. The microphone is wired directly to the APIM (Accessory Protocol Interface Module), which relays the microphone input to the ACM (Audio Front Control Module) through dedicated wiring. If the first command spoken is part of the ACM (Audio Front Control Module) voice recognition set, the ACM (Audio Front Control Module) retains control of the voice recognition and takes the appropriate action(s). If the first command spoken is part of the APIM (Accessory Protocol Interface Module) voice recognition set, the ACM (Audio Front Control Module) shuts off its own voice recognition and broadcasts a Controller Area Network (CAN) message to the APIM (Accessory Protocol Interface Module), transferring the voice recognition to the SYNC(R) system and providing the voice command that was spoken. The ACM (Audio Front Control Module) controls the voice engine for the base audio, navigation and climate control systems. The APIM (Accessory Protocol Interface Module) controls the voice engine for the SYNC(R) system (USB (Universal Serial Bus) port, audio input jack, and Bluetooth(R)).

AM/FM Antenna

A co-axial antenna cable connects the AM/FM antenna to the ACM (Audio Front Control Module).

Global Positioning System (GPS) Antenna

For vehicles equipped with navigation, the GPS (Global Positioning System) antenna receives information from satellites. The compass heading is also derived from the GPS (Global Positioning System) signal. A combination GPS (Global Positioning System) /satellite radio is utilized.

Steering Wheel Controls

The steering wheel controls consist of a series of resistors. Each steering wheel control switch function corresponds with a specific resistance value within the switch. When a switch is pressed, the reference voltage from the switch changes. This voltage change is monitored by the Steering Column Control Module (SCCM), which determines the requested function. A message is then sent from the SCCM (Steering Column Control Module) through the HS-CAN (High Speed Controller Area Network) to the BCM (Body Control Module). The BCM (Body Control Module) converts the high speed message to an MS-CAN (Medium Speed Controller Area Network) message and sends it to the ACM (Audio Front Control Module) (or APIM (Accessory Protocol Interface Module) ) over the MS-CAN (Medium Speed Controller Area Network).

Audio Input Jack

The audio input jack allows for a portable MP3 player to be connected to the vehicle audio system. When a portable MP3 player is connected, audio from the MP3 player can be played through the vehicle speakers.

Noise Suppression Equipment

The radio frequency suppression equipment reduces interference transmitted through the speakers by the engine ignition and electrical systems. When installing any new radio suppression equipment components, make sure that a good contact is made at all connections.

Audio Signals

Stereo signals contain left and right channel information and are used for most audio signals.

A mono signal is used for the microphone input to the APIM (Accessory Protocol Interface Module). The mono signal is also used for the voice prompts, the TTS (Text-To-Speech) feature, ringtones and any audio received through a connected mobile phone. These audio signals are output from the APIM (Accessory Protocol Interface Module) to the ACM (Audio Front Control Module). The mono and stereo outputs from the APIM (Accessory Protocol Interface Module) utilize separate circuits from the stereo output.

A digital signal transmits data from a media device connected through the USB (Universal Serial Bus) port to the APIM (Accessory Protocol Interface Module). The APIM (Accessory Protocol Interface Module) then converts the signal to analog and relays the signal to the ACM (Audio Front Control Module).

A wireless signal broadcasts audio signals from a Bluetooth(R) media device to the APIM (Accessory Protocol Interface Module), which converts the wireless audio signal to analog and relays it to the ACM (Audio Front Control Module).