Replacing the Remote Control Key Battery
REMOVAL
CAUTION
When removing the batteries, check whether the polarity is marked on the batteries. If polarity is not marked, mark the battery position.PROCEDURE

1. Insert a screwdriver into the gap between transmitter unit –1– and main key –2–.
2. Turn the screwdriver in the direction of the arrow to separate the transmitter unit from the key.

3. Release the transmitter unit by pressing the side latches (indicated by arrows). Remove the transmitter unit.

4. Using a screwdriver, detach upper battery –1– from holders –2–, as shown by the arrows.

5. Remove contact plate –1–. Turn it so that the two straight edges align with both latches. The contact plate can also be removed using a screwdriver.
6. Using a screwdriver, detach the lower battery from the holders. INSTALLATION
CAUTION
When installing the batteries, observe the polarity. Polarity (+/–) is marked on the battery and the housing.PROCEDURE

1. Insert lower battery –4– into housing –5– with the positive terminal (+) facing down. The positive terminal (+) is marked on the housing.
2. Place contact plate –3– on battery –4– and turn the rear latches.
3. Place battery –2– on the contact plate with the positive terminal (+) facing down and secure it.
4. Place transmitter unit –1– on housing –2– and secure it.
CAUTION
The transmitter unit is shown upside down in the illustration.5. Insert the assembled transmitter unit into main key –6– and secure it.
CAUTION
The key has a rolling code transponder, identified by the stamped letter W.Test yourself
A quick Audi A3 quiz: every answer comes with an explanation and a link to the manual page.