Sensor For Remote Locking - Where Is It?, Haynes manual appears to be wrong!

[mackay1]

The remote locking on my '96 (N) 2.5TD Exclusive doesn't work using either key plip. The Haynes manual says the sensor is located behind the roof light cluster but the part it shows appears to be the temperature sensor for the aircon rather than the remote sensor.

There's a possibility that this is a dual purpose component as it seems to be in two halves but I've already swapped it for a sensor known to be working on another car and that doesn't work (using the correct key).

Can anyone tell me where the sensor is and what it looks like please?

Thanks

Roy

[noz]

Hi Roy,

There have been two versions of the remote plipper receiver since the XM was launched.

Early cars had an InfraRed (IR) unit which must be in line of sight of the plipper for it to work. Hence it was mounted next to the central light. That way it was visible from about waist level all around the car through the windows. Of course the pillars provided blind spots too. I'm not sure of the exact distance but it was probably limited to 3-5m or so.

Later cars had a Radio Frequency (RF) unit which of course does not rely on line of sight to receive the signal. For a reason I don't know (maybe the size of the receiver) Citroen moved it to be underneath the glovebox. It is mounted on the steel crossmember. It is a black plastic box approx 50mm square by 25m high. The working range is close to 10m with new batteries in the plipper.

The point at which they changed from IR to RF is slightly woolly. I'm not sure it was as simple as Series 1/Series2. The information I have suggests it was in 1995. From your description it sounds like you have a Series 2 car and an RF plipper/receiver.

Please find attached the wiring diagram for the central locking and plipper receiver unit. It looks like it might have something to do with Fuse 34 or earth point M5. The fact that the central locking doesn't work even with the key suggests something common like the fuse or the earth. I would start there rather than the receiver. Armed with the wiring diagram you should be able to work your way around to narrow down the source of the fault.

cheers

noz

[mackay1]

Hi Norrie,

That's useful - thanks. I have access to a scrap S2 XM which I can take the receiver from (if I haven't already).

My message wasn't clear though - the central locking does work OK with the key. (I should have referred to "plipper rather than "key" - sorry.)

The car with the fault has a passenger airbag and I'd be really worried about removing that myself. Maybe it's a job for a dealer to do?

Cheers

Roy

[xmexclusive]

Hi Mackay1

Most if not all UK Mk2's have the U/Sound blip set with the receiver under the dash.
The blips and receiver are an electrically coded set and I have not yet found a way in to recode blips or receivers. So your spare is no use unless it comes complete with its blip(s) and then you have to swap the blip case to get the cars ignition key on the new blip set.
If you have an old type RF reciever in the overhead light fitting as well as the under glove box U/S receiver fitted to the car then the two may interact and prevent either system working.
If you try Citroen for U/S spares then you can get a replacement set (Rec & 2 matched blips) but they cost over £300. A new set fetched £206 on ebay last month. Citroen can supply replacement blips provided you quote the radio code no but these cost close on £100 each. I would caution on buying one of these unless you are certain that the receiver works properly.

Regards

XMexc

[mackay1]

Hi XMexc,

Thanks for your message. I have 2 spare blips and the receiver unit from a scrap car which I know were working OK.

My problem now is whether or not to try removing the glove box myself (and passenger airbag?) in order to replace the receiver unit - or if this is best done by a dealer.

Best wishes

Roy

[xmexclusive]

Hi Roy

So pleased you have obtained the expensive bits, well done as they are very difficult to come by from scrap cars.
Sorry I have never owned an XM with a passenger air bag so cannot be sure how difficult it is to dismantle safely. The drivers air bag and explosive seats have never caused me personally any problems with disassembly but that does not mean that I can recommend that you attempt your glove box. I can be reasonably certain that the receiver is under the glove box/ air bag of later cars as I can remember recovering the receiver from a scrap 97 car, that had a passenger air bag, a couple of years ago. All the air bag components have a 10 year requirement for inspection and retesting. I have yet to find an XM that has had this retest. There is usually a reminder sticker on the drivers door pillar which seems to get removed if it is overdue and the car is going to change hands. Perhaps other XM owners have some views on airbag servicing.

Regads

XMexc

[mackay1]

Hi EMexc,

It's interesting that you mention the 10 year life of the airbags as I was going to raise this in one of the fora here. The car I've just bought has only done 53k miles but is 1 month short of 10 years old.

In the manual it says it's very important to have both the airbags and the pyrotechnic front seat belt pre-tensioners replaced at 10 years. There's even a place for a maintenance stamp in the book for this. There's no mention of being able to have them retested though. Can you tell me more about this please?

I asked the local Citroen dealer to give me an idea of how much this might cost but so far I'm still waiting for an answer. Suffice to say though that he looked at me as if I was quite mad (maybe he's right!) He also said that they'd never replaced an airbag on ANY car - and this is a main dealer!

In most situations I can understand why this job never gets done - but given the mileage and condition of this car - I'm likely to hang on to it for 5+ years (with a bit of luck) - and given that I'm ferrying around the family in it it seems pointless to have airbags that might not work if needed.

I also wonder what they would replace them with. Presumably stock items that were manufactured around 10 years ago and have been sitting in storage ever since - so what's the difference I ask myself.

I know 5thGear - the Channel 5 motoring programme did a feature on this last autumn - but I missed it. Did anyone here see that programme?

Your input would be appreciated.

Many thanks

Roy

[xmexclusive]

Hi Roy

As you can see from the RP Nos. all my cars were manufactured in the year or so before yours. I went through the same thought process as you about a year ago and eventually with some reservations decided that there was no point in seeking replacement parts. Those that I was offered as new had similar manufacturing dates to those that were going to be replaced. A request to a specialist about a check and test was rejected as unnecessary. Only the most recently aquired working car had the 10 yr sticker so I did not worry about this when the other 3 reached the magic age of 10. It might be interesting to know the dates on the air bags in a car that is both over 10 years old and has had full main dealer maintenance.

Regards

XMexc

[mackay1]

In case anyone would like to know - I've changed the receiver and everything is now working fine.

The glovebox comes out easily without disturbing the passenger airbag - so this is a definate DIY job - 15 minutes and it was done.

Has anyone tried having faulty receivers plippers repaired?

Many thanks for everyones help.

Roy

[xmexclusive]

Hi Roy

I have been collecting orphan/dead receivers and plipers for a couple of years now. I guess I have about a dozen in total in a box to spend some time on one of these days. I have found the plipers a valuable source of spare cases to replace worn ones. I have done the usual checks for dry joints without repair sucess.

Last year I sourced an alternative new plipper/receiver set that I got to work reasonably well in one of the cars.

By this time I had canablised sufficient Citroen bits to have all the sets I needed so I put the alternative set with the made up conversion cable into the spares box for another day.

Regards

XMexc