Just replaced faulty trunk module and went for a drive - no audio! I can switch to all radio bands, nav, guide, and car functions, but no accompanying audio for anything? I used VCDS to scan the system and several modules did not communicate, includingthe radio. Not planning for another weekend of faux mechanic. . Does removing both batteries require initialization for any modules? Otherwise, I guess the sequential module failures has begun! My 2002 BMW 745 is faring better at 12 years senior and older tech! Any guidance would be greatly appreciated!

 

Sold my 07 750 Li because of the outdated audio and no Bluetooth. If your close to something, does your parking sensors sound off? I would go back and make sure the amplifier plugs are seated right (if the module you replaced is near it). Also check the amp fuse.

 

I had car on Bentley charger overnight and the final light was green. I removed the single 40A amplifier fuse (above starter battery for base sound system). Re-installed fuse roughly 15 minutes later, started vehicle, and received a "System Starting. . .) message onscreen. It took another few minutes, but audio returned to all functions. I pulled that fuse multiple times, but not sure if I tried it after the batteries were installed and for how long? Anyway, everything is functioning normally!