Audio System - DTC For No Communication To CD Changer
91 DTC in Various Control Units for No Communication to CD Changer91 12 33
2028570/1
January 31, 2012.
Affected Vehicles
Condition
A CD Changer is not installed by the factory and one, or all, of the following DTCs are present.
For TT & A3:
^ 56 - Radio - (00857) CD Changer Unit -R41- - No signal/communication
^ 37 - Navigation - (00857) CD Changer Unit -R41- - No signal/communication
For A6 & A7:
^ 19 - Data Bus On Board Diagnostic Interface - 6232 - U105E00 - Media Player Position 1 No Communication
Technical Background
Due to a global shortage of parts, during a specific period of the 2012 model year production, the factory installed glove-box CD Changer was not available to install. For some of these vehicles the PR Code "7A2" was not modified. PR Codes affect the automatic coding and parameterization performed by SVM. As a result, the factory coding of certain modules are not set correctly. Due to the incorrect coding, the control units constantly expect the CD Changer to be installed in the vehicle. These DTCs are normal for these vehicles. The PR Code "7A2" has not been changed for these vehicles and thus these DTCs will remain for the life of the vehicle. The coding can be manually changed for the affected control units but any future SVM communication will request a change of the coding back to the factory coding. A manual change of the control unit coding is not required.
Do not install a CD Changer in to these vehicles since the vehicle has already received a credit against its dealer invoice price. There is limited supply of the CD Changer service parts due to the global shortage and these parts are reserved for customers with actual CD Changer failures.
Production Solution
PR Code "7A2" has been removed from the PR string for vehicle built after this period.
Service
No repair is necessary.
Warranty
This TSB is informational only and not applicable to any Audi warranty.
Additional Information
All parts 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.