mk1 Xantia alarm ecu location

[aerodynamica]

Merry Christmas all, it's boxing day so inevitably I'm out in the garage having resisted it's charms since before Xmas
Anyway I need to look at the alarm ecu because I acquired a new IR remote that doesn't seem to be able to code to the sensor in the ceiling. Central locking all works via the for lock, as does dead locks.
So I suppose the central locking circuitry is all good. I think the recoding of the remote is dealt with by the alarm ECU (?) so need to check it's In good condition.

I expected to find the ECU under the passenger seat but the space appears empty. The alarm does work as I found out after reconnecting the battery. The override button works fine.

The IR remote is a new old stock item with no key blade fitted, has batteries and power and the IR sender can be seen to ' light' separate from the red led. I'm certain the remote works and sure its the correct type for mk1 (2 buttons, red led, and manufacturers name on the printed circuit is the same as the one on my previous Xantia. ) so all the sensible checks have been made.

Also: I'm reprogramming this by switching the ignition to 1 then aiming the remote to the sensor and holding for 40 sec. I'm sure this was what I had to do back in 2007 with my old 1.9d N-reg. Tried also with ignition switch to 2, and also pressing and releasing remote as well as holding it.

I am assuming the ceiling-mounted IR receiver functions.

So! I can't reprogram the remote!

Any help/ past experience greatly received!!

[aerodynamica]

Actually, perhaps its the ceiling IR receiver that learns the code? Just looked at that and it looks grubby it's covered in some semi-set kind of gray sealant and a bit of duct tape like it's been a bodge effort to keep water off it.. No sign of any leaks tho (it has been like a hurricane here)

[chinkostu]

They can be iffy to reprogram. Do you have a plip key already that works? I had to turn my ignition on and press the raised button while pointing it fairly close to the receiver. Took me a good hour to get both going, had one to lock and one to unlock at one point. But eventually it stuck, think i turned the key and pressed one key, then a small pause then the second key.

The central locking ecu is between the seats under the console, mine also has the alarm one under the passenger seat/rear passenger footwell. The roof mounted reciever can be swapped out without affecting the keys.

By the way citroen still supply cut blades for these keys!

[aerodynamica]

Thanks! Well, no I don't have a second remote - only a key. So what you found was that it takes many attempts? When I did this with my 95 Xantia it worked first time! In, igntion on, remote poit at receiver, half a minute later it was done.

Hmm. How much does the stealer ask for the blank key to be cut?

[citroenxm]

There is two box's for the locking Greame, the box under the PASSENGER seat carpet, useually needs the seat uplifting to find it, controls the alarm side of things but there is ALSO a box between the front seats, centre console, towards the rear, lift out the cubby box that sits over and around the sunroof and rear window switch's and there should be another box with two plugs in it.. this box is also central locking related too...

[aerodynamica]

Thanks but the central locking all works fine - it's just the recoding of the remote that isn't working. By the way had excellent results modifying the 2 height corrector cradles...

[citroenxm]

Brill Graeme, hope thats honest and not excellent as crap results!

I cant remember if the roof recivier stores the code of the locking box...

[wurlycorner]

Hmm. How much does the stealer ask for the blank key to be cut?

Bought one just a couple of months ago. Unfortunately I can't lay my hands on the receipt right now, but it was under £20 iirc.
Note that although they still do the keys, they don't do the fitting rivet for them anymore

[chinkostu]

Yea i had to recover my rivet unfortunately. They do need identification for cut keys.

I had 2 plips to program so mine was a pain. But as far as i know its ign on, within 20 seconds press button on plip close to receiver, then ign off and lock alarm car. Mine took quite a few attempts to do both though, from what i can tell it might roll the saved plips so you could eventually roll it back so no previous ones are saved, which is what i think happened with mine.

[aerodynamica]

Thanks all, will have a further go

[aerodynamica]

Tonight I was resealing a headliught and cleaning the rear light seals and greasing them up - getting a little water in through the off side rear light.. Anyway, back to the IR plip thing. A new pair of batteries saw no difference save for the red led pulsing stronger. I had a closer look at the IR receiver. And... it seems there's a problem!

This is what greeted me upon inspection:


An obviously burned-out track. The other side revealed the solder burned away:


So I now need to find a replacement IR receiver! Paul?

[chinkostu]

Looks like someones gone at it with a soldering iron, no obvious component failure anywhere (blown caps or melted plastics!)

Someones bound to have a spare. Otherwise you might have to run a length of wire to replace the burnt track!

[xantia_v6]

I think it is just a fatigued solder joint that has gone high resistance, then been passing enough current to get very hot. I suspect that the copper PCB track is not even damaged. It can't hurt to try resoldering it and see what happens.

[aerodynamica]

Hiya, it looks more like it shorted out between two of the connections to the plug - I think maybe due to water ingress. Anyway, I might be able to resolder itas it's only one track

[citroenxm]

Yes.. got a fair few about.. I owe someone else one as well. . Ill get one found for you greame!