Accessories and Optional Equipment: Description and Operation
Audio Module (AUM)
System Overview
Control Module
The audio module (AUM) manages functions for:
- Radio reception AM and FM
- CD playback (if the control module/car has either a CD player or a CD changer)
- Cassette playback (if the control module is equipped with a cassette player)
- Mini-Disk play back (option)
- TV reception (option, certain markets)
- RDS reception (certain models and markets)
- Voice information from the Road Traffic Information system, RTI (road traffic information) (option, market dependent).
The audio module (AUM) is mounted in the Audio Box in the center console. The control module is integrated with the sound unit.
They are replaced as one unit.
There are three different sound units:
- HU-4XX: Integrated radio, cassette player and internal amplifier (4x25 W)
- HU-6XX: Integrated radio, cassette player, CD player and internal amplifier (4x25 W). Available options: external amplifier and external CD changer
- HU-8XX: Integrated radio, 4 disc CD-changer, internal amplifier (1x25 W) for the center loudspeaker and requires an external amplifier (4x50 W). An external CD changer is available as an option.
The CD player has next/previous track, fast search forwards and backwards and random play (RND - random).
The cassette player has next/previous track, fast forward and backward and random play (RND - random).
The Mini-disk player (option, Japan only) has next/previous track, fast search forwards and backwards and random play (RND - random).
The audio module (AUM) communicates with directly connected components and with other control modules and components connected via Controller area network (CAN) communication.
RDS-reception (Radio Data System) is possible (market dependant) during FM transmissions. In the USA, the system is called RBDS (Radio Broadcast Data System).
The loudspeakers in the front and rear doors are connected to the control module or to an external amplifier if applicable. The loudspeakers in the parcel shelf are also connected to the control module or to an external amplifier (if applicable). There are three different loudspeaker options:
- Base Performance
- High Performance
- Premium sound.
The control module continually checks both its internal operations and its input and output signals. A diagnostic trouble code (DTC) is stored in the control module memory if the control module detects a fault in any of these. The diagnostic trouble codes (DTCs) can be read off using the diagnostic tool via the data link connector (DLC) in the car.
The audio module (AUM) has an internal communication system called Melbus. There is communication between the audio module (AUM), CD changer, Road Traffic Information Module (RTI) and the TV receiver.
Melbus comprises three different signals:
- MSCK, the clock signal
- MDATA, the data signal which transmits information
- MBUSY, indicates whether the data signal is busy or not.
Signals
The above table summarizes the input signals to and output signals from the audio module (AUM). The signal types are divided into directly connected signals and Controller area network (CAN) communication. The illustration displays the same information with the Volvo component designations.
Design
Location of components
1. Radio antenna. Integrated in the rear windshield
2. Antenna amplifier FM/AM, located in the D-post
3. Loudspeakers, positioned in the parcel shelf
4. Keypad in the steering wheel for audio and telephone
5. Center loudspeaker with display for cars with the Road Traffic Information module (RTI)
6. Center loudspeaker for cars without a Road Traffic Information Module (RTI)
7. Audio module (AUM) - Sound unit audio
8. Door-mounted loudspeakers front (treble)
9. Door-mounted loudspeakers front (bass/mid-range)
10. External amplifier, positioned under the right-hand front seat
11. Rear door-mounted loudspeakers
12. Antenna amplifier for the bumper antenna
13. FM antenna integrated in the bumper
14. CD changer audio.
Antenna
The audio module (AUM) has an antenna system for AM and FM. This consists partly of an AM antenna and partly of a dual antenna system for FM (Diversity reception). The dual antenna system is used to reduce Multipath interference. One antenna is integrated in the rear windshield. The other antenna is integrated in the rear bumper. The signals from the antennae are amplified or adjusted by each individual antenna amplifier.
External amplifier
The 4X50 W amplifier is positioned under the right-hand front seat. It is used to amplify the audio output signal. The external amplifier is an option for the HU-4XX and HU-6XX. The amplifier is installed as standard with the HU-8XX.
CD changer (option)
The CD changer is mounted on the left-hand side of the cargo compartment. The changer can take ten discs in a special magazine. The CD changer has disc selection, next/previous track, and random play (RND - random). The CD changer is controlled by the audio module (AUM) and is connected to the control module by connectors. The signals between the audio module (AUM) and the CD changer are transmitted via Melbus communication.
Remote control
Remote control from the key pad on the steering wheel is available as both an option and as standard equipment depending on the market. The keypad is positioned on the right-hand side of the steering wheel and is connected to the steering wheel module (SWM) via serial communication. It is possible to control the volume (increased/decrease) and change the preprogrammed radio stations via the keypad. The buttons are used to select a track when playing a CD, cassette or Mini- Disk. The steering wheel module (SWM) communicates with the audio module (AUM) via the Controller area network (CAN).
Audio remote control (option)
Remote operation from a separate wireless remote control is available as an option. This can be used to control the volume (increased/decrease) and change the preset radio stations. The buttons are used to select tracks when playing a CD, cassette or Mini-Disk and to change the CD when using the CD changer. A particular frequency can be searched for, radio stations stored in the presets, Autostores made and sources stored.
The remote control is fitted with two AAA (LR03) batteries.
Function
The audio module (AUM) functions as a sound unit in the car and is also connected to other control modules on the Controller area network (CAN). The audio module (AUM) receives the vehicle speed signal via the Control area network (CAN). Volume increases with speed (if the function is selected; the function can be switched off).
If a factory-installed carphone (option) is installed, the audio module (AUM) is muted during telephone calls.
If an accessory electronic module (AEM) is installed, the audio module (AUM) is muted if either a handsfree telephone is used (accessory) or back-up gear is selected if the car has a back-up warning system (accessory).
If the car has the Road Traffic Information system (RTI) (option), voice information is played back through the existing loudspeaker.
The keypad for remote operation (option) on the steering wheel is directly connected to the steering wheel module (SWM) via serial communication. The remote control keypad is on the right-hand side of the steering wheel. It is possible to control the volume (increase-decrease) and change the preprogrammed radio stations via remote operation. The buttons are used to select a track when playing a CD, cassette or Mini-Disk.
The steering wheel module (SWM) communicates with the audio module (AUM) via the Controller area network (CAN).
Diagnostic Functions
General
The control unit has built-in diagnostics, Volvo Diagnostics, that continually monitor the control unit and the input and output signals.
Diagnostic trouble codes
If the control unit detects an error, it stores a diagnostic trouble code. There are 36 diagnostic trouble codes in total. An error that was detected the last time the engine was running is defined as permanent. Other detected errors are defined as intermittent.
Reading and erasing diagnostic trouble codes
Stored diagnostic trouble codes can be read and erased using this facility.
Erasing diagnostic trouble codes can only be done when all the diagnostic trouble codes have been read at least once.
Reading and erasing the user information
Stored user information can be read and erased using this facility.
-4201 Focusing error
- CD inserted the wrong way
- Condensation in CD-player or on disc
- Faulty CD
- Faulty CD player
-4203 Servo error
- Read-out error in CD player
- Faulty CD
- Faulty CD player
-42F1 Disc feed error
- Dirt in CD compartment
- Faulty CD
- Faulty CD player
-42F3 Pick-up error
- Faulty CD player
-4301 Focusing error
- Condensation on MiniDisc or in MiniDisc player
- Faulty MiniDisc
- Faulty MiniDisc player
-4303 Servo error
- Read-out error in MiniDisc player
- Faulty MiniDisc
- Faulty MiniDisc player
-43F1 Disc feed error
- Dirt in MiniDisc player
- Faulty MiniDisc
- Faulty MiniDisc player
-43F3 Pick-up error
- Faulty MiniDisc player
-4401 Focusing error
- CD inserted the wrong way
- Condensation on CD or in 4-disc CD changer
- Faulty CD
- Faulty 4-disc CD changer
-4403 Servo error
- Read-out error in 4-disc CD changer
- Faulty CD
- Faulty 4-disc CD changer
-44F1 Disc feed error
- Dirt in CD compartment
- Faulty CD
- Faulty 4-disc CD changer
-44F2 Error in selecting CD
- Faulty CD
- Faulty 4-disc CD changer
-44F3 Pick-up error
- Faulty 4-disc CD changer
-4501 Cassette feed error
- Dirt in cassette compartment
- Faulty cassette
- Faulty cassette player
-4601 Focusing error
- CD inserted the wrong way
- Condensation on CD or in 10-disc CD changer
- Faulty CD
- Faulty 10-disc CD changer
-4603 Servo error
- Read-out error in 10-disc CD changer
- Faulty CD
- Faulty 10-disc CD changer
-46F1 Disc feed error
- Faulty CD cartridge
- Faulty CD
- Faulty 10-disc CD changer
-46F2 Error in selecting CD
- Faulty CD
- Faulty 10-disc CD changer
-46F3 Pick-up error
- Faulty 10-disc CD changer
Reading the control unit identification
VADIS identifies control units by reading the number of codes from the control unit memory.
The codes contain information on the control unit:
- hardware component number (control unit without software)
- hardware series number (control unit without software)
- software component number
- diagnostic software component number.
Downloading Software and Replacing The Control Module
New software can be downloaded into the audio module (AUM). New software must be downloaded when replacing the audio module (AUM). Unlike other control modules, there is no software available for reloading the audio module (AUM). Only software for the addition of applications is available. When ordering software, the hardware and the software in the car is compared to the Volvo central database. If the comparison is OK the software is downloaded into the audio module (AUM).
If the comparison between the car and Volvo central database is not OK, the database is updated with the car configuration. When this is complete the software is downloaded.