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