Audio System - Satellite Radio Fades In and Out
Satellite Radio (SDARS) Error Messages and Satellite Drop Out Diagnosis
91 06 23 Oct. 24, 2006, 2011500/2. Supersedes technical service bulletin Group 91 number 06-13 dated Jun. 1, 2006 due to updated information.
Condition
Customer states that at times the reception of satellite radio drops out or fades.
Technical Background
Reception for satellite radio may vary depending on vehicle location relative to physical obstacles that block the signal path to the antenna. Both satellite radio providers use terrestrial repeaters (largely in metropolitan areas); in the cases where the signal path tends to consistently be blocked. The tuners also have memory buffers which compensate for short term signal blockages lasting a few seconds.
Long term blockages caused by trees, buildings, tunnels, parking structures, or even large vehicles, can result in temporary loss of the signal. This will be reported by the customer as a "drop out." Several error messages may appear in the radio display or MMI due to technical or system design. Use the following error message definitions when diagnosing a satellite issue to rule out Satellite Dropout issues or basic system functionality.
SIRIUS: LINKING
XM: UPDATING
These messages will normally appear during a complete signal dropout, but here are 2 possible causes external to the car for these messages:
- Channel List Update "Provider sends out a new list of channels due changes in the channel offerings. This usually only occurs 1-2 times per year and only lasts at most 2-3 minutes
- Change of Subscription Package - The customer changes their subscription options
SIRIUS: ACQUIRING SIGNAL
XM: LOADING
This occurs when the signal is seen but is too weak to produce full audio output. This should last less than a minute in most cases.
SIRIUS and XM: NO SIGNAL
There is absolutely no usable signal available at that specific vehicle location and time.
SIRIUS and XM: NO SAT
This is displayed when the car does not recognize that there is a tuner installed. Please confirm the tuner is properly installed and functioning properly.
Satellite Constellation Configuration
Sirius has 3 satellites flying in figure-8 orbits that cross over the US and Canada. There are always two Satellites directly over the US. As they orbit, when one satellite is coming into the broadcast region over the US, the other satellite is moving out of the broadcast area. During this rotation there is a half an hour window in the morning on the east coast with obstructions where the signal may tend to drop out on a regular basis.
XM has 2 geostationary satellite locations positioned directly over the equator. This creates very consistent signal loss patterns due to the static satellite configuration.
This graphic shows the location of the two geocentric XM satellites above the equator, and the 3 Sirius satellites and their orbital paths.
Terrestrial Repeaters: To counter dropouts due to satellite patterns and building obstructions, both XM and Sirius have terrestrial repeaters which rebroadcast satellite signals. These increase the likelihood of reception in tunnels and other areas where normal satellite reception would not be possible.
Production Solution
Not Applicable
Service
To confirm that the complaint is a dropout issue, gather the following information and check the system for these conditions:
Signal Loss Event Information:
- Is the dropout repeatable day after day?
- Does it occur in the same location(s) and time of day?
- What geographical features are in the area? (buildings, dense foliage, canyon...)
- What error message is displayed in the radio screen/MMI?
Vehicle System: No DTC's are present in the Satellite Tuner or Satellite related faults in the radio in any vehicles.
- A4 and A4 Cabriolet up to MY 2007, allroad, TT up to MY 2006: The following MVB Description does not apply because there is no Gateway (J533).
- A3 MY 2006, A6 MY 2005, A8 MY 2004, and on and Audi Q7 MY 2007: If possible, use the following MVB description to check the Signal Status to observe the signal strength to confirm a dropout event.
Customer: If the system is operating as designed based on this TSB, explain how the system works and that this is considered normal operation. No repair is necessary.
If there is a consistent signal dropout in specific areas, advise the customer to report the specific time, location, and length of dropout to the respective provider who may consider installation of terrestrial repeaters in certain cases.
Warranty
This TSB is informational only and not applicable to any Audi warranty
Additional Information
Refer to the following Technical Service Bulletins for further information:
- 2011760 - TPMS Warning Light On and/or No Satellite Radio (R146) with Audi Navigation Plus
- 2011641 - Radio is Inoperative in Satellite Mode, Vehicles without J533 (Gateway)
- 2011913 - Radio is Inoperative in Satellite Mode, Vehicles with J533 (Gateway)
- 2012017 - Satellite Radio (SDARS) Activation Information
More information on Satellite Tuners can be found in the following resources:
- ElsaWeb >> Service Net >> Additional Information >> Accessory Parts Installation Instructions
- Satellite Tuner Matrix in Access Audi
All part and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Dept. and service manuals for the latest information.