C5 Mark 2, what happens when you unlock the doors?

[Quackers]

Went to my C5 (2007 173BHP 2.2) pressed the unlock door button on the remote and this very loud ticking/catching noise came from the engine bay and lasts about 5 seconds. At first i thought it was something to do with suspension pump as C5s start rising from when you unlock the doors unlike the Xantia etc, but making the suspension go up and down does not make it do this noise. Opening the doors makes it happen most of the time, and turning the ignition to the one before starting position makes this noise go wild and fast. Also when you stop the engine it makes this noise. It sounds like its coming from the centre of the engine area.

So what moves in the engine when you unlock the car, open a door, pre-start the engine, stop the engine? and also every few minutes whilst the engine is running?

I would say everything is normal when driving , only thing that felt odd was the engine seemed to judder when being switched off.

Any ideas?

[VertVega]

When I unlock the doors of the car,
- the mirrors unfold,
- ECU wakes up (interesting technical sounds from some where in engine bay)
- I guess also the air condition flaps arrange their positions,
- Instrument panel wakes up
- if the interior lights were on (in use) they they are also switched on.
During this initialization process it also adjusts the height if it has lost the height set level.

When I unlock the doors of the car,
If I don't open any doors or get in the car for some time (engine not started) then the car locks all doors, folds the mirrors and ECU switches to sleep mode.

Edit: I guess folded mirror feature is not available in all C5 II models.