Xantia Alarm is driving me mad!!!!

[kentc5]

lol...
as title says, I am fed up... ,
the alarm is working, all the doors lock and all the windows are closed etc.
Bonnet closed
Boot closed
even fuel flap is closed.

When I try to lock it, a beep from the alarm horn comes on ... I know this noise is made when a door is not closed properly. .. but I opened and closed everything 2 and 3 times and it did not help.

I have the suspision that might be the boot door... but how am I going to check>?

[Mandrake]

Two ways to tell. If you have access to a Lexia it will tell you the state of all door locks so will immediately tell you where the culprit is.

If you don't have one but suspect it is the boot you can disconnect the cable to the boot switch which should make the alarm think the boot is closed.

The switch can be accessed easily by removing the black trim at the boot opening, (the bottom trim, not the one that raises with the boot door) the switch is just to the right of the stationary boot catch.

[citroenxm]

Remove the boot trim, and unplug the sensor, its a tiny one Identical to the bonnet switch's on the bonnet catch's.

I beleve unplugging the sensor is the defenate way of telling the ECU the boot IS closed... like a "forced Close"..

If not, the only other doors monitored are front doors ONLY! and of course one or both of the bonnet catch's ....

Back doors are not monitored...

[horsedentist]

Citroen sensors for doors work on open circuit when shut. ie. The micro switches open not close so you can unplug them one by one to find the culprit had the same problem with my window sensor on tailgate of the wife's C5 it was on the rock so to speak. So you closed the tailgate and it was fine then it would creep and make a curcuit with the vibration of driving and then the computer started screaming that the tailgate was open usually when you were in the fast lane of the motorway and unable to do anything about it! Drove me crazy till I packed the switch out to raise it about an 1/8th of an inch problem solved.

[kentc5]

Don't know if it helps ... but I removed the negative pole on the battery on Sunday to reset an ABS light ... (I know I have an ABS sensor faulty as well ... so that needs replacing)
Would that make the alarm in a default state?
Ie beeping once when arming ... as well as the hazard indicators blinking once?

So if this is the case is there a sequense to disable to audible arming seting?

[Mandrake]

I've checked the programming of my alarm on the Lexia and as far as I can see there is no option to enable an always on audible arming or disarming sound. Disconnecting the battery will also not affect the programming of the alarm in any way.

It is possible however to disable the "door still open" chirp with a Lexia so that it won't audibly alert you to a door being left open when arming the alarm. Probably not a good idea though as you won't know when a door is genuinely left open...

Disabling the alarm entirely so it doesn't arm when locking with the plip is also possible with a Lexia.

[kentc5]

are the alarm sensors on the doors, the same interior light switches? or are there are two sets of swithces per door? one for light and one for the alarm?

[Mandrake]

Good question. The alarm does monitor the door open/close switches of all four doors for breakins, (the Lexia live sensor data shows the open/close state of all four doors which I assume is the light switches) but there are also the central locking switches in the front doors connected to the lock buttons which monitor whether the doors are locked or unlocked seperately from being closed or open. If one of the front doors fails to lock when arming the doors will all unlock again and the alarm will bleep. Try leaving a front door open when you lock with the plip and you'll see what I mean, the doors will all lock and unlock again.

Once armed either opening any door or unlocking a front door without opening it (even with the correct key) will set off the alarm, so I have to assume both open/close switches and unlock/lock switches are monitored.

I assume the interior lights go out when all four doors are closed ? If so the door open/close switches should be ok. I also assume that both front left and front right door locks/buttons operate the central locking, and that when you lock the doors they do not immediately unlock again ? If so the door lock switches are ok.

That only leaves the bonnet and boot switches as culprits, both of which can be unplugged to identify the guilty party...

[citroenxm]

For info.. there's no door light switches.. the door sensors are built into the door locks themselves ...

[kentc5]

I will do some tests today and come back with the results...

[kentc5]

OK .. here it goes
All the doors lock with out problems
All the windows are closed
The bonnet closes properly
The boot closes properly and locks too.
The fuel flap locks too
The interior light and the light on the dash they go off once all the doors are closed.

Once I arm the alarm it beeps!

If I unlock with the key and not the fob the alarm starts waking up the neighbour as it should be....
So everything works as it should be apart from the blinking beep! lol

I cannot see where the cable is in the boot lid, it is not on the boot floor as all the electric etc seem to be on the boot door latch mechanism??
I cannot understand how it switches on the light ... as it comes on when the door is almost fully open, hence it is not latch activated?

No idea either where the bonnet switch might be?

[Mandrake]

The boot light is activated by a mercury tilt switch which is in the tailgate itself, thus tilting when the tailgate opens. The switch for the alarm is completely separate.

As I mentioned earlier the alarm switch is mounted to the right hand side of the stationary latch - you remove the half dozen torx screws that hold the black plastic strip/bumper that runs across the back of the boot and surrounds the stationary tailgate latch - the switch is driven by the plastic piece that depresses down around the latch loop via a wedge, thus the downwards motion of the plastic pushes the stalk of the switch to the right.

It's a bit of a flimsy mechanism which looks like it would wear quite easily. The connector is right on the switch itself and is a standard automotive connector with a wire clip. The adjustment of the boot catch is important for the switch to operate correctly.

As for the bonnet switch - your guess is as good as mine! I'm told its mounted in a similar way to the boot switch near the stationary catch but I have not been able to find it - my boot switch works but my bonnet switch is faulty, so I can arm the alarm with the bonnet open without any complaining blips...of course its possible that my bonnet switch may be missing entirely...

From what you describe it must be either the bonnet switch, boot switch, or both.

[citroenxm]

The bonnet switch is hidden a bit but if you undo the two 10mm bolts holding the bonnet catch you will then see the switch below it.. Im not 100% sure if there's a switch on both catches or just one...

[Northern_Mike]

I've had this 3 times with various Xantias. Once it was the boot switch (Rattiva - Jim solved it, I just used to leave it unlocked), one was the bonnet switch, and the other time was when I locked the cat in the car overnight.

[kentc5]

Tomorrow when I am back from work as long daylight is there still I will have a look at them