Sometimes after replacing the Bluetooth Module (under the driver seat A8 or Q7), the Phone would pair to the car, but the steering button, sound and microphone don’t work, most of the time, the settings on the Bluetooth module wasn’t done correctly. You do need an OBDII like VCDS (VAG-COM) to enable it again.
- Telephone Coding Address 77 – should be set to 100900 then 100970 then back to 100900 and do soft MMI restart – Setup+Big Round Button+ Upper right MMI selector.