Many failures in the Xsara Picasso

Hello, how are I new in this forum and I would like to see if someone has happened to someone so that I could orient myself.

I have an Xsara Picasso of 2005, a few days ago when the trunk opened it did not open, as I had to take things from it I opened it manually inside.

All other doors do open with the command but the trunk does not make any noise and does not open.

The trunk light does not work, I could observe it by manually opened the trunk.

The next day I realized that the "courtesy" lights of the interior of the car did not turn on when I was commanded to open the car, when before, both the front and the rear if they did and they did not turn on when you open the door of the car or when you take away the key of the contact that I did before.

When climbing the car prescribed, both, to turn them on manually and they did not go, I thought they had melted but when putting the key in the contact and clicking again in them they went on.

Also the same day I observe that the air conditioning pulls hot air, does not cool, which to date, worked perfectly.

The next day I see how in the panel it puts me, without having anything on or radio, or lights, just putting the key in the contact without starting, "activated economic mode", staying a few seconds fixed the battery light, then disappearing both things and working the vehicle perfectly.

The car also emitted a sound if you opened the door, for example of the co -collection, before stopping the car, but it does not emit it either.

So I read the economic mode is activated when there is something that is consuming battery, but if I do not go or the lights when the car that can be consuming?

When I have the battery 8 years I have changed it but nothing works, I do not know if I would have, I think no, to configure something to reset all the values ​​"the computer" or something similar.

If someone had any idea where I can look, I have already looked at the fuses and they are ok.

Thanks in advance.

Greetings to all.

To open and close the trunk in those cars the cables are cut and everything that goes to the rear gate stops.
Look at the gums that unite Porton and a car that on the right usually carries the cables to see if there are cables cut.

You can activate the economy mode playing on the menu, it makes you stop radio on 2 minutes automatic and some more things.

We are softening vehicles that carry a Comfor <- that carries everything related to the interior of the vehicle. If there are cut or worse cables to dough, it is crazy and that's why I think it fails. And I do not remember but if it is Cambus Safe system, it is losing codes or sending them halfway.

Thank you about the cables I have also tried to see them since they are lined but I think I will have to look better, although in principle or nothing cut.

The most less economic way is for what it is but the funny thing is that it turns on when I have everything turned off and only having the doors open, but I insist all off, lights, radio, etc ...

The system that takes no idea, I know only that it carries diesel and little more hehehehe. I am not very specialized in this mechanics.

These vehicles incorporate a unit called BSI that is responsible for lights, alzavidrios, distance opening, etc., this unit brings mounted as around 8 to 10 fuses, but this unit fails and those things happen, it is the most causes but you must also check the negative terminal of the checked battery that is well tight and not sulfatado.

In the end I have taken it to the mechanic, according to them and after making several checks they say it is the BSI, they still have to check something tomorrow, but they are inclined to that, the € 600 joke.

I will wait for tomorrow in case there was another solution but for now I will not fix it, there is not the oven for buns.

Thank you all