Cell Phone - Poor Voice Recognition/Hard To Hear Call
91 Microphone Testing Tips
91 11 16
2026895/2
October 5, 2011.
Supersedes Technical Service Bulletin Group 91 number 11 - 97 dated July 15, 2011 for reasons listed below.
Affected Vehicles
Condition
Customer complains of one of the following:
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^ During a Bluetooth call the other party has trouble hearing them.
^ Voice recognition accuracy is poor.
Technical Background
This TSB provides guidelines for testing microphones in a vehicle.
Production Solution
Not Applicable.
Service
1. Investigate GFF to determine if a fault is stored for microphone operation in address words 56, 5F, 67, or 77 depending on vehicle and equipment
levels.
2. If a fault is stored in GFF, proceed with the test plan outlined in the scan tool. If there is no DTC stored, proceed to step 3.
3. Verify the complaint by using one of the following methods:
a. Pair a known good compatible Bluetooth phone to the system, and place a call to a landline contact. Place the call in the same conditions as the
customer concern (driving, stationary, A/C on, etc.).
If the call quality for the other person is clear and without distortion, then the microphones are OK and should not be replaced. If noise or
distortion is heard, then proceed to step 4.
b. Create a directory contact and then a voice tag for that entry. Create the voice tag in the same conditions as the customer concern (driving,
stationary, A/C on, etc.). Playback the entry and verify it is clear and without distortion.
If the entry sounds clear, then the microphones are OK and should not be replaced. If noise or distortion is heard, then proceed to step 4.
4. Check the microphones for mechanical defects:
a. Remove the roof module and verify the microphones are securely seated in the roof module by pressing on them. For 2012+ C7 & D4 vehicles,
remove the microphones and inspect the rubber seal around the edge of the microphone. Verify it is not torn or broken. If it is damaged, replace
the microphone. For vehicles equipped with integrated seat belt microphones, please reference TSB 2026851, 91 Belt Microphone Overview.
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Note:
When installing microphones back into the roof module, make sure the microphones are installed straight into the cavity. Installing them at any other
angle can cause damage to the microphone and/or seal.
b. Inspect the microphone wiring and verify it is securely fastened in place and that there is no visible sign of damage.
5. Check the microphones for electrical defects:
a. Disconnect the microphones and verify the voltage coming from the module is 8V +/- 10%.
b. Disconnect the microphone cable at the control module and verify that the voltage on the wiring to the microphones is 0V.
c. If voltage is present in step a. and step b., then inspect the wiring for any shorts.
d. If voltage is not present in either case, or the incorrect voltage was measured in step a., then inspect the control module for proper output
voltage at the module and replace if necessary.
e. If both step a. and step b. were OK, then replace the microphones.
Warranty
This TSB is informational only and not applicable to any Audi warranty.
Additional Information
The following Technical Service Bulletin(s) will be necessary to complete this procedure:
^ TSB 2026851, 91 Belt Microphone Overview
^ TSB 2026888, 91 Bluetooth Phone: poor call quality
^ TSB 2027718, 91 Bluetooth Phone: call quality poor at other end
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.
