NO SOUND / AUDIO TROUBLESHOOTING

🔊 If the screen works but there is no audio, the cause is almost always one of the following:

✅ AUX not selected
✅ Car Bluetooth audio not enabled
✅ MOST fibre optic cable not transferred
✅ Audio output setting incorrect in the screen menu
✅ Using screen mirroring (AirPlay/AutoLink) but expecting Bluetooth sound

1️⃣ First Check: Is AUX Selected in the BMW iDrive Menu?

On the BMW iDrive system:

MEDIA → External Devices → AUX

If AUX is not selected, you will not hear any sound from CarPlay/Android Auto.
📌 Tip: Some vehicles require you to plug the included 3.5mm AUX lead into the factory AUX socket.
🟢 If you hear sound after selecting AUX → ✅ Fixed
🔴 If still no sound → continue below

2️⃣ If Your Car Supports Bluetooth Music Playback

Some BMWs allow audio to play through original Bluetooth instead of AUX.
To enable this:
On the new screen:

Settings → System → Use Car’s BT Channel = ON

Then:

Hold MENU for 3 sec → return to OEM iDrive
Go to MEDIA → External Devices
Select your phone name (not AUX)

✅ This will route audio through BMW Bluetooth instead of AUX.
⚠ This only works if your original BMW already supported Bluetooth music (not just calls).

3️⃣ MOST / Fibre Optic Cable Check (VERY COMMON CAUSE)

If the car has a factory optical cable loop, it MUST be moved into the new quadlock harness.
[Image – MOST cable location placeholder]
✅ If ignored → no sound at all, even if everything else is correct.
If you have no AUX + no Bluetooth audio + SOS error → this is almost always the issue.

4️⃣ USB Audio (iDrive 6 Only – Optional Upgrade)

If you're using the optional USB audio interface box:

AUX from harness plugs into USB audio adapter
USB adapter plugs into BMW USB port
Select USB in BMW iDrive media menu

[Image – USB audio box diagram]
✅ Sound quality is better than AUX
✅ Only available on ID6 vehicles

5️⃣ Screen Mirroring = AUX Only (No Bluetooth Sound)

If using:

AutoLink (Android mirroring)
AirPlay (iPhone mirroring)

➡️ Audio does not output through Bluetooth
➡️ You must use AUX
Fix:
Settings → System → Use Car’s BT Channel = OFF
Then select AUX in BMW menu

6️⃣ Quick Sound Diagnostic Table

Symptom	Likely Cause	Fix
CarPlay/Android Auto connected but silent	AUX not selected	Select AUX + retry
OEM radio sound works, new system silent	MOST cable not moved	Transfer fibre optic
Sound works in OEM but not new screen	AUX lead not connected	Check 3.5mm pass-through
Bluetooth connected but no sound	Phone connected only for calls	Switch to AUX or BT music
Mirroring video plays but no sound	BT used instead of AUX	Disable BT channel + use AUX

7️⃣ If Still No Sound

Before contacting support, please send:
✅ Photo of quadlock wiring (showing MOST cable if present)
✅ Photo of AUX passthrough connection
✅ Screenshot of Settings → System → Audio Output on the screen
✅ Photo/video of BMW iDrive media menu showing selected source

Nov 4, 2025