How to replace remote fob battery in Audi A4, A5, Q7 and TT

December 22, 2017 in Audi A4, Audi A4 B9 (2015 - ), Audi A5, Audi A5 F5 (2016 - ), Audi Q7, Audi Q7 4M (2015 to 2018), Audi TT, Audi TT 8S (2014 - ) by admin

This tutorial explains how to replace the key fob battery in Audi A4 B9 (2017 and 2018), Audi A5 F5 (2018), Audi Q7 2nd Gen. 4M (2017 – 2018), Audi TT 8S (2016 – 2018) with key fob pictured below (smart key).

LED in the remote control key (arrow in image on right side)

– If you press a button briefly, the LED blinks once.
– If you press and hold a button (convenience opening/closing), the LED blinks several times.
– If the LED does not blink, the remote control key battery is dead. The message “Remote control key: replace
key battery” can also appear in the instrument cluster display. Replace the battery.

To replace remote fob battery you’ll need:

– new CR2032 3v battery (one battery)


In order to replace it, follow the steps:

Step 1: Press the release button (A) and remove the mechanical key from the remote control key.

Step 2: Press the release buttons (C) on the battery holder while pulling the battery holder out of the remote control key in the direction of the arrow.

Step 3: Re-install battery, and slide the battery holder carefully into the remote control key. Insert the mechanical key.

Battery orientation is with the (+) side down.

The instructions in this tutorial will work in the following model years:
– Audi A4 B9 2017 and 2018
– Audi A5 F5 2018
– Audi Q7 2nd Gen. 2017 and 2018
– Audi TT 8S 2016, 2017 and 2018