Audio System (G427239)

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The audio system is based around an Integrated Head Unit (IHU) which communicates on the Media Orientated System Transport (MOST) ring and the medium speed controller area network (CAN) bus.

The IHU contains the following functionality:

• Radio tuner.
• CD player (Six disc in dash changer).
• Integrated telephone control.
• Auxiliary input (for any device featuring a 3.5mm jack plug output).

The IHU (Integrated Head Unit) unit also integrates with the navigation system, this requires the addition of a navigation computer, touch screen display and GPS antenna.

The IHU is woken up by CAN bus activity and is not woken up from the ignition aux position.

The IHU is the Bus Master for the MOST system and contains the timing master for the MOST system.

Connector C1354 Pinout Table For High Line Audio

Connector C2115 Pinout Table

Tuner

The IHU incorporates a AM/FM tuner which allows for 18 FMpre-sets and 18 AM (9 MW and 9 LW) pre-set stations to be stored in the IHU memory. The radio tuner also incorporates the following radio functions:

• Auto tune
• Traffic announcements (TA)
• radio data system (RDS) EON function
• Seek station
• Tune up/down
• Scan
• PTY

CD Player

The CD player is a 6 disc in dash mounted device. The CD multi changer is capable of playing commercial CDs, CDRs, CDRWs and MP3 discs.

Random Play

The Random feature only works on the CD, which has been selected. The Random feature plays all the tracks on the selected CD in a random order. All the tracks on that disc will be played before a new random sequence is played. If a new CD is selected while in random mode, the random mode will be cancelled and play will commence from track 1.

Repeat

The Repeat feature allows the current track to be repeated in an endless loop, when selected by the user.

MP3

The CD player has the capability to play MP3 files. The MP3 discs follow a format of folders and files within the folder. It is also possible to place all the files in the root directory on the CD.

The random and repeat features follow the normal CD random and repeat feature functions.

Scan

Scan allows the user to play the first 10 seconds of each track on the CD in the unit.

Automatic Volume Control - AVC

The AVC feature is designed to adjust output volume to compensate for the rising level noise of the vehicle as the vehicle travels faster.

There are 10 settings for AVC, where 0 = off, 1 is the lowest setting (minimum volume change with speed and 9 the maximum).

The vehicle speed signal is used to enable the IHU to calculate the volume adjustment required. The vehicle speed signal is received over the CAN. The signal is an average of the four wheel speed sensor signals.

Control of the AVC is carried out by the audio amplifier.

Should an invalid speed signal be received the AVC will not alter the output volume.

The IHU contains the master clock functionality. The IHU contains and displays the clock in one unit. Other vehicle modules that require clock functionality use the time supplied from the IHU.

The clock is available to any control module that is connected to an interconnecting bus i.e. either of the CAN busses or the MOST ring.

The clock display configurable to show in AM / PM or 24 hour format. Midnight is shown as 12:00AM or 0:00 respectively. The default condition, if not specified, after power on or delivery, should default to 1:00PM or 13:00. Depending upon the market set the clock will default to either 12 or 24 hour format.

The time is adjusted from the IHU. Under conditions when any bus could be asleep or shut down, the HMI does not allow clock adjustments.

The audio system has three amplification options dependant on the audio system specified:

• Internal amplifier
• Harman kardon
• Harman kardon LOGIC 7

The amplifier is located under the RH front seat and is connected to the audio system via the MOST bus. Speaker connections are hardwired.

Speaker Connector C0491 for Harman Kardon Amplifier

Speaker Connector C0491 for Harman Kardon Logic 7 Amplifier

Speaker Connector C0492 for Harman Kardon Amplifier

Speaker Connector C0493 for Harman Kardon Amplifier

Speaker Connector C0492 for Harman Kardon Logic 7 Amplifier

Speaker Connector C0493 for Harman Kardon Logic 7 Amplifier

The IHU can be remotely controlled via steering wheel mounted controls. The audio steering wheel controls are mounted to the RH side of the steering wheel with the voice recognition system control (push to talk switch) located on the LH side of the steering wheel behind the speed control switches.

The Steering wheel control switches allow the driver to:

• Change audio system mode
• Adjust audio volume
• Change CD tracks
• Activate the voice recognition system
• Change radio pre-sets
• Tune up/down
• Answer and end a phone call (where a phone is fitted)
• Use the voice recognition system.

The switches operate on a resistive ladder principle. A voltage is supplied to the switches and dependant upon which button is pressed a reduced voltage is returned to the head unit.

The SDARS systems operate in the S-Band frequency range (2.3 GHz) and, as a result of the use of satellite transmission have the ability to provide CD quality audio broadcasts over very large areas (typically continents). SDARS service providers transmit a signal from their up-link facility (which is the original point of transmission of data, voice or other information through an antenna system) to a satellite where the signal is then down linked to both the terrestrial repeater network and the individual SDARS car radios. The radio switches between the satellite signal and the repeater signal depending on the strength of the signal at any given time.

Land Rover will be using the Sirius Satellite Radio service provider in the USA.

The Sirius SDARS systems comprise:

• Satellites
• Ground repeaters
• Up-link ground stations
• Radio receiver systems

The Sirius SDARS system uses three satellites on an inclined elliptical orbit. This ensures that each satellite spends approximately 16 hours a day over the continent of the USA, with at least one satellite over the country at any one time.

The satellites beam their signals down to the ground where the signal is picked up by receivers or is transmitted to repeater stations to cover built up areas where the signal is obscured.

The TMC system is a European only system whereby traffic information is received by the TMC tuner and used by the navigation computer to recalculate the route being used to avoid the traffic disruption. This system information is broadcast on the RDS data carriers.

The information is used by the navigation system to avoid traffic disruptions on a planned routeFor additional information, refer to: Navigation System (419-07 Navigation System, Description and Operation)..