Cell Phone - Volume Intermittently Lowers During a Call
91 08 1162017028/2
November 11, 2008.
Supersedes Technical Service Bulletin Group 91 number 07-63 dated December 20, 2007 for reasons listed below.
Affected Vehicles
91 Phone volume lowers intermittently during call
Condition
The customer may report a decrease of the volume during a call. When compensating the lowering volume with the volume button, the customer may encounter a sudden jump of the volume to an elevated level. This happens intermittently and with several different cell phone models.
Technical Background
The telephone preparation module has an echo cancellation function implemented to avoid acoustic feedback. In extreme cases, such as when a customer speaks very loudly, directly into the microphone (located in the roof module), the echo cancellation may lower the volume to inaudibility.
Production Solution
Not applicable.
Service
1. Confirm that the customer's cell phone is on the Audi compatibility list.
2. Observe the customer making a phone call in the vehicle.
3. If the customer's voice is raised strongly during a call and/or if the customer's voice is directed toward the microphone in the roof module, explain that digital cell phone technology allows users to talk in normal conversation volume and that the microphones are positioned to allow the driver to face traffic.
4. If the customer insists on having the ability to speak loudly during a call, the sensitivity of the microphone can be adjusted in the 77 telephone module.
a. Select Adaptation channel 131 in the telephone module (Address word 77).
b. The sensitivity of the microphone can be lowered with the values shown above.
c. Change and save the adaptation value.
Tip:
We recommend 130 as a starting point
d. Verify in several test calls with the customer that the telephone system is functioning to his/her satisfaction now. If necessary, change the sensitivity to a higher or lower level.
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.