The Gen1 remote key fob is unable to unlock the car. How can I synchronise again?

[RacingNight]

I am experiencing a problem with the key remote on my 2008 R8 V8. Specifically, the remote is unable to unlock the doors, while it is able to lock the doors and access the front baggage box. I feel the key needs resynchronization since it is clearly communicating with the vehicle, but is only able to lock the doors and open the hood.

The problem originated from an incident a year ago when I parked my vehicle next to another 08 R8 V8, and its alarm went off at 3am. In response, I took both car keys and hit the buttons on each key for around 45 seconds to deactivate the alarm. The next morning, both keys had the aforementioned problem, however one was resolved while the other remained unresolved. My hypothesis is that the computer has restricted communication access with the key due to its suspicion of tampering.

The key batteries have been tested and are functioning well with a voltage of 3.10v. However, the red light on the key does not illuminate while locking or unlocking the baggage compartment. I have attempted to use both sets of keys and have also replaced the batteries with fresh ones.

Both vehicles start and operate well, however, they need the use of the key to open the doors.

Does anybody has the knowledge of how to synchronise the keys for this device?

Expressing gratitude!

[Ledgerciao]

Are you certain that your automobile battery is in good condition?

[RacingNight]

Yes, I do a monthly trickle charge on it and its current voltage is 12.7v.

[MundeDas]

The key fob is unlikely to be the cause. It is likely that the door lock actuators need to be changed. It is a frequently seen component that tends to malfunction in Audis from this time period.

[RacingNight]

One of the vehicles consistently locked and unlocked without any issues for the whole year, starting from the initial problem until this weekend. During that time, I replaced the batteries in the key fob to see whether the issue with the second car was caused by a faulty battery. The second vehicle key failed to function properly, and when I reinserted the battery into the first car key fob, it has been unable to open the doors ever since.

The indicator lights illuminate each time the lock button is used, and the doors will lock if they are not already locked. However, when any of the keys' unlock buttons are pressed, there is no response - no indicator lights flash and the doors do not open.

The red indicator light on all keys fails to illuminate at any point, even after securely locking the doors.

I also replaced the door lock actuator 6 months ago.

The automobiles are not fond of having another key fob from a very identical car used nearby, since it triggers the security mechanism to lock out the keys.

[Darthilli]

Try this on the RS4 and see if it works.

1. Insert the key into the lock.
2. Engage the car's locking mechanism by rotating towards the back.
3. Insert the key into the lock and turn it to the locked position. Then, press the lock button on the fob.
4. Unlock the automobile by turning the key towards the front.
Step 5: While the key is in the unlock position, push the unlock button on the fob.
6. Initiate the vehicle by using the key.
7. Power down the vehicle and synchronise the fob.

[Authorce]

This is a great steady @Darthilli. Exclamation of surprise or disbelief.

[RacingNight]

Superb! I will attempt it!