Reset a Frozen Infotainment Screen

Last updated: June 10, 2026

If the MMI display in your Audi A4 (B9/8W, 2015–Present) has frozen, gone black, or stopped responding, you can force the system to reboot yourself in well under a minute — no garage, no tools, and without losing a single setting.

Which MMI is in your B9 A4

The B9 A4 spans two infotainment styles. Pre-facelift cars (2015–2019) use the dash-top MMI screen driven by a rotary controller on the console (MMI Navigation / MMI Navigation plus, with the touchpad-equipped dial on higher trims). The facelift (2019–on) swapped that for a dashboard MMI touch display you operate by tapping the glass. Either way, a freeze is almost always a software lock-up in the head unit, not a dead screen, and the volume-knob reboot works on both.

Soft reset (reboot) the MMI

Do this parked, with the ignition on so the unit keeps its power.

1. Find the volume knob on the centre console (beside the rotary controller on pre-facelift cars; near the gear selector on facelift cars).
2. Press and hold the knob — keep pressing straight through the point where the audio mutes.
3. After about 10–15 seconds the screen goes black.
4. The moment the Audi rings logo appears, release. The system is rebooting.
5. Wait up to a minute for the home screen to reload; audio, Bluetooth and media return on their own.

On pre-facelift rotary cars you can also reboot by holding the MENU/SETUP soft key, the rotary push-dial and the top-right soft key together for about 10 seconds.

Will this erase anything? No

The reboot is completely safe. It does not wipe your radio presets, navigation favourites, paired phones, or any settings — it simply restarts the head unit’s software, exactly like restarting a phone. Use it as often as the MMI plays up.

If the MMI stays frozen

• Hold longer. If 15 seconds did nothing, try again and hold a full 20–25 seconds before releasing at the logo.
• Let the car sleep. Switch off, lock it with the key, and walk away for about five minutes so the electronics fully power down; then unlock and restart.
• Check for a software update. Audi issued several MMI firmware trains across the B9 run; a dealer can flash the latest build if yours freezes repeatedly.
• Pull the fuse (last resort). With the car off, the infotainment fuse can be removed for 10 seconds and refitted to force a cold restart. Only do this if the knob-hold won’t respond at all — check the manual’s fuse list for the head-unit position.

Factory reset (erases data — rarely needed)

A factory reset is separate from the reboot and only worth doing if you are selling the car or chasing a deep, persistent glitch. Go to Settings (via the dial on pre-facelift cars, or by tapping on facelift cars) and look for Factory settings / Reset MMI / Delete personal data. It erases presets, paired phones and navigation history, so only do it deliberately.

Frequently Asked Questions

How do I know if my B9 has the rotary MMI or the touchscreen?

Pre-facelift B9s (roughly 2015–2019) use a fixed dash-top screen driven by the console rotary controller; the 2019-on facelift has a touch-operated dashboard display. The volume-knob reboot works on both; only the rotary cars also offer the three-button combo.

Will I lose my radio presets or sat-nav favourites?

No. The volume-knob reboot keeps every preset, navigation favourite, driver setting and paired phone. Only the menu-driven factory reset clears them.

The screen is stuck on the Audi logo — what now?

A unit looping on the four rings usually needs a full power-down. Hold the knob for 20–25 seconds; if it still loops, lock the car and leave it five minutes, then restart. Persistent boot-loops point to a firmware update being due.

Is it safe to drive with the MMI frozen?

Yes. The MMI is separate from the engine and driving systems — you only lose audio and navigation. Reboot once you are safely parked.

My MMI keeps freezing every few days — why?

Recurring freezes on the B9 are usually an out-of-date software build or a flaky phone pairing. Have the dealer update the MMI firmware and try deleting and re-adding your Bluetooth/CarPlay connection before suspecting the hardware.

If a warning light or fault message stays on the dash after the reboot, it may have stored a diagnostic trouble code — you can look it up on autodtcs.com.