Xantia 97 immobiliser problem

[serenity]

Hi all, first post on this forum as my 97 Xantia TD is causing me grief. The problem started when both lights on the immobiliser key pad lit up and the car would not start. This was intermittent. So I took it to my local citroen garage. A mechanic there disconected the pad so that the car starts without it, problem solve so off I went ( done for free!!!!!!!). Now we have an intermittent start problem the car will start most of the time but then on occasions it won,t as if the immobiliser is working. To get it going each time I now have to disconnect the battery to re-set the car, it will then start ok until next time. Do I need to replace something or can I get the whole alarm/immobiliser disconnected? We don't need the alarm as we live in rural france.
Hope someone can help? The car by the way has not got the key off switch under the bonnet but it is a mark one.

[Carsten S]

Hi,
Immobilizer problems are often related to the connectors in the inner-wings. The plug corrode, and the keypad loss connection to the engine management box.

[Xaccers]

Pretty sure on the TD, the immobiliser is all on the pump, behind the anti tamper shielding.
Basically it just stops 12v going to the stop solenoid preventing fuel from flowing.
Removing the keypad while the engine is running disables the immobiliser.

With the immobiliser active the engine should turn over on the starter but just not fire.
Is that what you're getting, or are you getting no turn over when you turn the key?

If it's the latter, then your starter motor is kaput.

If the engine turns over but just won't start, then you'll have to remove the pump to drill off the sheilding and remove the immobiliser, then wire up an ignition switched 12v feed to the stop solenoid.
Or, get an earlier pre-immobiliser pump from a scrappy or ebay, replace the seals in it while it's off the car, and then swap pumps, wiring up a 12v switched feed for the stop solenoid.
If you search long enough you can find one which is semi electric like yours but no immobiliser, early 96 I believe, otherwise an earlier one will work fine, but you'll just have the ECU light on the dash as your ECU won't be able to fine tune the pump timing. Cassy has an older pump fitted to her so the ECU light is on all the time. It is just saying "Hey, I can't talk to the pump"
Then with a re-sealed pump, you should have no problems at all running on vegetable oil.

[serenity]

The engine turns over but will not start. So I guess it is the immobiliser on the pump. I think removing the pump is alot of work though I might have to speak to my friendly local mechanic. Unless there is another alternative?

[serenity]

Had a look in the haynes manual and there is no mention of the immobiliser being connected to the fuel solenoid I assume they have ommitted it as the car they are working on is earlier. Can I not get to the immobiliser with the pump still attached? It looks pretty easy? Anyone managed todo this is?

[CitroJim]

Can I not get to the immobiliser with the pump still attached? It looks pretty easy? Anyone managed todo this is?

Nope. The immobiliser module is a black encapsulated lump that sits above the stop solenoid and is protected by the armour. Removing the armour is a pump out job only. I've seen where attempts have been made to do it in-situ with disastrous consequences. The armour is hard and will shatter. In one case a piece broke off, flew and ended up in the inlet tract of the engine. It wrecked it beyond belief.. Also I've seen pumps smashed beyond repair.

To de-armour, you must remove the pump and drill out the tamper-proof bolts with a hard drill and as you drill and remove the ones in the distributor head you MUST replace them such that the distributor head is held by at least two new Torx high-tensile bolts at all times diagonally opposite. Otherwise you risk breaking the HP pumping element.

This website shows how to de-armour in a few pictures...

If you don't feel confident doing this, remove the pump and take it to a diesel specialist or engineering firm for the job to be done.

I can't stress how much risk there is in completely ruining the pump if you don't go about the job with great care.

[xmexclusive]

Sounds like the intermittant problem you originally had is still there.
All the dealer did by dissabling the keypad is stop the keypad lights showing.
At least when you had the keypad lights working they showed you when the fault was present and saved you flattening the battery.
Try the dealer again and ask why the fix did not work.

John

[wheeler]

Is this a later 1.9td engine with semi electronic control & an ECU ?
If both keypad lights were on this is telling you the keypad is not talking to the pump/ECU.
Most of the time this means the ECU is not being powered up or loosing its earth so disconnecting the keypad wont work in this case, usual possible causes of this are corroded/rotted wires under the radiator, poor engine or body earths, intermittant fault with the double relay, poor connections at the inner wing connectors.

[serenity]

Yes I believe it would be the later 1.9td. Another person today also told me to check the earths. I will have a look at the weekend.