A4 Alarm Randomly triggers and key fobs not responding

[jcollin5]

This is a bit of a weird one.

The Alarm on my A4 (51 plate) goes off randomly (maybe once a day or less). This is more likely when it's cold or wet and almost always first thing in the morning. Trying to switch it off using either key fob rarely works first time. It actually took about 50 attempts the other day at which point we took it to our local Audi dealer. They are also a bit stumped as the diagnostics seem to be pointing towards a problem with the rear door deadlock (I'm not convinced that this would cause the other symptons).

Here's some other points.
- The key works in the driver door and the boot
- the car will start and can be driven for a short distance with the alarm going until the imobiliser cuts in (trust me, no choice, angry mob gathering at early o'clock)
- trying to unlock the car using the fobs often sets off the alarm and then renders the fobs fairly useless.

My thoughts are either a loose sensor or damp/cold in the sensor that detects the key fob signals.

If anyone else has a more educated idea then I'd love to here from you.

Many thanks...

[Mr V]

I've had a few convenience control modules cause faults similar to this. Usually, but not every time, it's due to water ingress into the passanger footwell where the module is located by a block plenum chamber.