Xantia Wierdness

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D.Slatford
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Xantia Wierdness

Post by D.Slatford »

Hi all, I wonder if anyone could shed some light as to whats happening here. I've had issues with the keypad immobiliser on and off for ages, and the alarm, in recent weeks though the immobiliser is jammed off (green light on with ignition) and won't budge. Additionally, the red alarm warning light has always been on continually with the ignition since I bought the car last year.
I just tried disconnecting the battery for a while to perhaps reset some confused circuitry. This had nill effect on the immobiliser, but a strange effect elsewhere. The red alarm warning light flashed when power was reapplied even with the engine started, and more strangely the dipped headlamps flashed on and off with it - I've never seen it do that before. Headlamps stopped flashing with the engine on, the red led continues. Turn engine off, headlamps flash again. Get out of car and close door again - everything stops. Then back to square one -red led is on continously with the ignition.
Is something just screwed? The keypad? The alarm unit (wherever the heck it is)? The ECU? (gulp). All three? Another oddity I've found is that sometimes, after turning off the ignition and opening the drivers door, a relay clicks on and off within the ECU. Close door, it stops. That seems intermittant. The keypad usually beeps when you stop the engine. Battery seems to be in good condition.
higgy
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Post by higgy »

Can't help with the keypad as my car doesn't have one.By disconecting the battery and reconnecting it you have set the alarm,if my memory serves me correctly you have to swith on the ignition and then press the ultrasonic overide button on the switch panel to the right of the steering wheel within ten seconds this should turn the alarm off.
Dave Burns
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Post by Dave Burns »

If it's the genuine Citroen alarm it's under the carpet under the front passenger seat.
Good luck with it, from that description of the fault's you're going to need it.
Dave
alan s
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Post by alan s »

Spooky stuff; The only suggestion I can make is to check out for a problem in a PCB.
I used to own a CX that had central locking. We could be driving along when all of a sudden the doors would lock ... then unlock. I could lock the car, walk two paces & hear it unlock & sometimes relock again. Most times if we left the car parked anywhere we would come back to an unlocked vehicle.
I disconnected it and eventually spent ages on it after an auto electrician had given up. We found that a drop of water had found its way into a control box behind the ashtray & had shorted the printed circuit board. A clue to this was a very small battery drain shown on the meter with everything disconnected or switched off. The way we isolated it was by having the meter connected and removing the fuses one at a time until the meter zeroed. Then it was a case of a component check.
Another possibility in your case worth considering is the fact that it appears to have been doing this since you purchased the car in which case there is always a chance of "human intervention" by the previous owner or his repairer that could ad a whole new dimension to trying to find the problem.
Alan S
D.Slatford
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Post by D.Slatford »

<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>
Spooky stuff; The only suggestion I can make is to check out for a problem in a PCB.
<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>
Which now the weathers cleared up I'm doing, have the thing out, there *might* be one or two dry joints so I'll resolder it shortly. But I've discovered something interesting - there's two plugs which this thing attaches to, a grey and brown one. Off the wiring from the brown plug, there's two individual black leads, which connectors attached which appear to mate with each other. I found them disconnected. Does any xantia alarm experts know what these are for, and whether I should plug them togeather? It's sooo tempting, like the Big Red Button that says do not press :) I'd love to know the purpose of these connectors first though..
Dave Burns
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Post by Dave Burns »

The black leads sound like they could be for the ultrasonic sensor's.
Iv'e replaced these in the door's of my car and they have a single black lead attached.
While you are in there Daniel, have a look for any adjustment pot's that might alter the sensitivity for the ultrasonic's.
Good luck
Dave
D.Slatford
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Post by D.Slatford »

<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>
The black leads sound like they could be for the ultrasonic sensor's.
Iv'e replaced these in the door's of my car and they have a single black lead attached.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>
Can't find any pots, everything solid state and mostly surface mount components. Have resoldered a couple of very minor suspect dry joints and put it all back, no change. The red light is still on all the time with the ignition, the alarm still doesn't sound. I whipped out the keypad too, but that immobiliser is still jammed off. I'll have a go at joining those two wires togeather in a moment. Interestingly, despite the car dating from '95, the alarm ECU has a '97 sticker on it and the immobilser keypad '96. Also, under the keypad, there's two yellow plugs bound in foam - what're these for? I'm guessing some kind of test point, there's nowhere they plug into.
Dave Burns
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Post by Dave Burns »

Don't think Iv'e ever seen a dry joint to a component that didn't generate heat, resister's, transister's, relay's and the like.
Have you checked the ultrasonic dissable switch on the dash and does your car have the key switch in the scuttle pannel, then there is the siren though can't imagine it causing such trickery but you never know, think that's behind the plastic liner in the n/s front wheel arch.
The two plug's are more than likely for optional equipment, hydractive, autobox or whatever.
When you start taking things to bit's you find them all over the shop.
For instance the LX is wired for electric rear windows, even into the door's, so being as it was that easey I stuffed em in :o).
Dave
D.Slatford
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Post by D.Slatford »

<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>
Don't think Iv'e ever seen a dry joint to a component that didn't generate heat, resister's, transister's, relay's and the like.
<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>
There's a couple of higher wattage resistors in there, although I've seen dry joints on other things before that don't generate heat, depends on the quality of the orignal join. Case in point, the xantia remote keyfob, seems almost everyones had theirs go on the blink due to poor soldering. Mine included, still, I cannot trace where the heck the faulty connection lays, but it's there somewhere, it works perfectly outside the case yet highly intermitantly inside.
<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>
Have you checked the ultrasonic dissable switch on the dash and does your car have the key switch in the scuttle pannel, then there is the siren though can't imagine it causing such trickery but you never know, think that's behind the plastic liner in the n/s front wheel arch.
<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>
Yep, I used that to silence the alarm before disconnecting the battery - and yes, I did re-enable it again! (it's produces a split-second noise presumably to tell me it's reactivated). After having taken the brave step of connecting togeather those two loose plugs by the alarm ECU - absoloutely nothing happened or changed. I think I'm going to have to scout around for a cheap second hand alarm ECU and swap it out now. Ditto the keypad, maybe even the engine ECU depending on where <i>that</i> fault lies - can one engine ECU simply be swapped out for another, or does it require some setting up with some kind of equipment before hand? Another thing I'd love to know is what those relays are that click sometimes in/around the ECU after turning off the engine and opening the drivers door..
Dave Burns
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Joined: 14 May 2001, 05:30
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Post by Dave Burns »

Don't know about the engine ECU, but if one was working ok in the same model of another car, I would think it would swap over providing you know it's code.
As for the clicking relay, is the light's on buzzer working ok when the door is opened and do the courtesy light's work ok.
A family member had a 405 where there was a rapid clicking somewhere inside the car, if you sat perfectly still it would stop, turned out to be the ultrasonic sensor's detecting movement and operaring a small relay, don't think it was a line fit alarm though.
Dave
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