Audio System - No Sound in CD or Radio Mode
91 08 902013107/5
November 10, 2008.
Supersedes Technical Service Bulletin Group 91 number 07-05 dated February 20, 2007 for reasons listed below.
Affected Vehicles
91 BOSE Sound System without function, no sound
Condition
A BOSE Sound System-equipped A6 produces noise or no sound in CD and Radio mode.
The Gateway control module may store DTC 00463/004 for no communication with the BOSE Amplifier J525.
Technical Background
The BOSE amplifier may be stuck in MUTE with the MUTE symbol displayed on the MMI screen. White noise or a high-pitched noise may be another indication of this issue.
The condition can usually be reversed via power supply reset to the amplifier. Only BOSE amplifiers with software version 0140 are affected.
A ring break diagnosis may not identify the amplifier J525 as defective. The VAS Tester may not be able to communicate with the BOSE Amplifier while in this condition.
Production Solution
Improved software.
Service
Verify if the issue is present in all Audio modes.
Reset the BOSE amplifier by disconnecting and then reconnecting the BOSE amplifier connector.
NOTE:
Ensure that terminal 15 / ignition is turned off before disconnecting the amplifier connector.
If the sound returns or the noise disappears and Software Version 0140 is verified in the BOSE Amplifier J525 (Address word 47), an MMI System - Update has to be performed. Therefore use Update CD 4F0 906 961 AB, which can be obtained in the ETKA parts catalog.
MMI Update procedure
1. Connect a recommended battery charger to the designated charging posts in the vehicle.
NOTE:
To avoid false readings of the battery manager, don't charge the battery directly at its posts.
2. Eject possible inserted CDs from the CD changer in the glove compartment and load Update CD 4F0 906 961 AB in position 1.
3. All sound settings will be set to default after the update. Depending on the installed MMI components, further settings (Previous/Memory station list, stored CD name, directory entries and voice recognition name tags) may be lost.
Tip:
Write down all settings to restore them after the update. Inform customers that they have to rerecord their name tags.
4. Press and hold the MMI Control Head - buttons: Setup and Return simultaneously until the screen appears as shown.
5. Press the lower right soft key of the MMI Control Head to enter the SWUpdate menu.
6. Use the Central Control knob of the MMI Control Head to select CD-ROM and then Standard.
7. The screen above, which may take a few seconds to appear, shows the current software status of the MMI component in comparison to the inserted Update CD.
8. Scroll down the component list with the Central Control knob and select Start download.
9. Note and obey the displayed message to avoid component breakdowns, and scroll down the screen to accept the following update with OK.
10. The MMI component update lasts between 5 and 60 minutes, depending on the installed components.
11. After initialization of the updated components, the following screen (or a similar one) appears.
NOTE:
The displayed status Not OK and - is update-related and not a fault. Please ignore and proceed.
If you scroll down the component list you may encounter, that not all necessary component updates were performed in the first step (e.g. 1 NOK). In this case, select Try again to perform the missing component update.
If all necessary components are updated (0 NOK) select Restart MMI to reset the MMI system.
12. Eject Update CD 4F0 906 961 AB and re insert removed CD's, if applicable
13. Connect the VAS Tester to the vehicle and erase all sporadic fault codes
14. Select 07 - Display/control unit and add 32 to the adaptation value of adaptation channel 2. The battery charge status will then be displayed again.
NOTE:
The battery charge display in the CAR menu is off by default with the new software.
15. Perform the required SVM Update using action code NA4FK730
For further SVM update instructions and troubleshooting, please refer to the SVM Operating Manual; ElsaWeb TSB 2011732.
Warranty
Required Parts and Tools
All part and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service manuals for the latest information.