S2 Xantia Activa - immobiliser probs

addo · Post by **addo** » 02 Jul 2011, 11:44

How is your alternator?

Also - the car cranks; are you getting any injector action or sparks?

Post by **CitroJim** » 02 Jul 2011, 18:42

getting hold of a keycode Mike is a dealer job. Go see one and if they're good then no worries. take some ID and the car's V5C (Reg Document) to prove who you are and that the car is yours.

Xac successfully obtained the code for Juliet by visiting a dealer and today I programmed his keys and remotes using it. I had no issues at all but one thing i discovered is that whilst the CPH is in programming mode (i.e the Lexia is speaking to it) there are no bleeps, the immobiliser light never comes on and the central locking fails to work. Once the lexia is disconnected from the CPH all then returns to normal. In fact in programming mode it behaves exactly as yours is!

I did not see the initial error message you had about results cannot be guaranteed and so on.

I fear your CPH is either suffering a fault or it's somehow stuck in programming mode.

When you get the code (a four digit alpha-numeric) entered by using the Lexia up and down cursor keys there is absolutely nothing to loose in trying to re-program them.

I know that's not a good answer Mike but I trust my observations may help a tad...

Fingers crossed the re-program works

wheeler · Post by **wheeler** » 02 Jul 2011, 21:28

superloopy1 wrote:
superloopy1 wrote: VIN is VF7**************[VIN obfuscated, can be read by forum staff], is anyone able to tell me what the hashed keycode would be for the car?
Anyone?

Try T4FE

superloopy · Post by **superloopy** » 03 Jul 2011, 21:18

Thanks Wheeler, that concurs with a code I obtained on another forum so i'm confident that it is correct.

Jim, I fear the worst but still do not understand how this immobilieser/alarm business works? What 'bits', for want of a better word, intercept the plip signal and then disable the alarm initially? I believe my car is still alarmed but if that was the case then would i still be able to enter the car and if so would the key be recognised or not? What's the worst case scenario, which bits would i need to swap and i'm assuming a lexia would come in handy if i need to reprogram any parts? I'm going to give it a go tomorrow now that the lexia trolley is accssible to the car ..... wish me luck. I'm assuming that with a CPH dialogue then electrics are not considered a problem? You've got to bear in mind that the car hasn't moved (been started regularly with citaerobics performed on a regular basis, without any problems) for some time but this battery buisiness may mean it's reached the end of its shelf life

Post by **CitroJim** » 03 Jul 2011, 21:36

Mike, as I understand it and I may not be quite right as MK2 Xantias are not my strongest subject, the CPH is a central controller that amongst other things looks after the alarm, central locking, immobiliser, interior lights and no doubt other esoteric matters as well.

Basically it contains a radio receiver to listen for the key remotes and decode them and if the signal is in agreement with it, performs the alarm and locking functions. It also works in harness with a transponder box that 'reads' the ignition key chip via the aerial around the ignition barrel to determine if it should de-immobilise the engine ECU when the ignition is switched on.

I believe that the Engine ECU, the CPH and Transponder are a matched trinity and cannot be exchanged piecemeal to isolate a problem. I may be wrong and some elements may be swappable but that question will need to be answered by someone with a better understanding than me.

There's an awful lot of wiring involved so it could still be a wiring issue. I can do you some diagrams if that would help?

The CPH and Transponder are not very accessible though. They hide up under the passenger airbag. It might just be worth checking all connectors are secure on the modules.

Also hiding along with the CPH and Transponder is the Trafficmaster module. That's an easy one to spot as it says what it is on the box.

andmcit · Post by **andmcit** » 03 Jul 2011, 21:51

http://www.ebay.co.uk/itm/120744791885

shame to see such a decent car broken but this will have the CPH ECU
Key with trasnsponder and aerial to fit a new set but my hunch would
point to a split in the loom from the battery box to the CPH.

superloopy · Post by **superloopy** » 04 Jul 2011, 13:53

CitroJim wrote:Mike, as I understand it and I may not be quite right as MK2 Xantias are not my strongest subject, the CPH is a central controller that amongst other things looks after the alarm, central locking, immobiliser, interior lights and no doubt other esoteric matters as well.

Basically it contains a radio receiver to listen for the key remotes and decode them and if the signal is in agreement with it, performs the alarm and locking functions. It also works in harness with a transponder box that 'reads' the ignition key chip via the aerial around the ignition barrel to determine if it should de-immobilise the engine ECU when the ignition is switched on.

I believe that the Engine ECU, the CPH and Transponder are a matched trinity and cannot be exchanged piecemeal to isolate a problem. I may be wrong and some elements may be swappable but that question will need to be answered by someone with a better understanding than me.

There's an awful lot of wiring involved so it could still be a wiring issue. I can do you some diagrams if that would help?

The CPH and Transponder are not very accessible though. They hide up under the passenger airbag. It might just be worth checking all connectors are secure on the modules.

Also hiding along with the CPH and Transponder is the Trafficmaster module. That's an easy one to spot as it says what it is on the box.

Jim, thanks for the info.

Wiring diagrams might help, whereabouts is the engine ECU located. Is it in the box under the bonnet alongwith the suspension electronics? Is the CPH ecu also the aerial/receiver for the plip then, there's no separate aerial?

Andrew,

Thanks for that link, i've PM'd the seller see what's on offer, i've asked for VIN code if possible to allow me to check suitability.

superloopy · Post by **superloopy** » 04 Jul 2011, 15:41

Had a quick look behind the glovebox this afternoon. Nothing visible that looks like a cph or transponder. Difficult cos I've no idea what I'm looking for, anyone any pics? Does the passenger airbag come off without removing the dash, I'm hoping so because If not that would certainly be her death. Is the aerial ring which reads the key chip also part of the so called trinity or is it a swappable part? Does anyone know the ID of a good cph, mine is coming up as unrecognizable but appears able to still communicate, maybe just a red herring?

addo · Post by **addo** » 04 Jul 2011, 17:24

The "aerial ring" as you call it, is not a coded part.

Not 100% on the passenger funbag removal but on many cars there are sacrificial clips holding the cover on - you pop the cover, remove the airbag/tether and access is good. Fit two new clips on reassembly and it's like a bought one.

You do have the glovebox itself out, right?

andmcit · Post by **andmcit** » 04 Jul 2011, 17:58

The CPH sits tight up on the bulkhead once the glovebox is removed as
Adam rightly states - there are some hidden screws under the glued
carpet to hunt out when removing this! The ECU box sits on lugs on the
heater box and spare cable length is very short so it's a slight PITA
BUT not grounds fir scrapping the car just yet!! I got to the point where
I could swap everything (including ECU) in 30 mins on my crocked V6.

I changed the universal aerial ring just to rule it out as this is the vital
link in recognising the chip in the key.

superloopy · Post by **superloopy** » 04 Jul 2011, 23:10

Looking a tad better this evening after running a full lexia session against the CPH. Identification is still showing as 'ecu not recognised' but I managed to run every dialogue against the ecu without any problems.

Even managed to prove that the key warning LED is still functioning! Armed with that success i proceeded to reprogram the keys and ECU with the obtained keycode (T4FE), again without problems.

Once this lot had finished I had a breakthrough, of sorts. The plip now works to arm/disarm the car, beeps when it should and flashes the lights on opening. The key however is NOT working, no recognition at all.

I've got a new aerial 'ring' on order just in case but i'm beginning to lean towards the transponder as the CPH 'seems' to have passed with flying colours. However, I cannot obtain a dialogue with the engine ecu, is this due to the fact that the key hasn't been recognised, the ecu is therefore locked during my lexia session? Or symptomatic of a problem with engine ecu maybe?

Is the transponder ONLY used to pass the key details to the CPH or does it aso get used during the plip process which would rule out my theory? Or ... is the plip frequency acting directly onto the CPH to arm/disarm/unlock/lock etc and NOT needing the transponder for any part of its process?

Anyone?

I'm still interested in seeing what's what behind the glovebox which is now out but I cant see any way to remove the passenger airbag, any assistance appreciated (Andrew

).

If the engine ecu lives life among the airbags, what are the two ecu's that are boxed under the bonnet, front left as you look into the engine bay? Presumably one is suspension ecu?, What's the other?

That's all for now, thanks all, feel as though a bit of progress has been made today

andmcit · Post by **andmcit** » 04 Jul 2011, 23:32

Hi Mike,

The plipper did stop working anything on my v6 where before it worked
effortlessly (best on any other Xant!) prior to the car deciding to stay
stopped permanently.

You've managed to move further forward than I managed with mine!
The 'ECU not recognised' is the message I kept getting on it and was
the similar issue that was fixed on the Green Goblin with wiring under
the battery fusebox.

FWIW, you don't need to touch any airbags - access is a bit tight but if you
look up towards the scuttle at the back above the heater box you'll see a
yellow (IIRC - or maybe orange) multi-plug with a large spring loaded clip
locking it tight. I even wondered if the scuttle was leaking water in mine
through onto the CPH...

The ECU's:
Engine ECU lives under the bonnet, suspension is the other and the smaller
ECU's are the fuel relays.

I believe although I cannot confirm this, the transponder only works to
unlock the ECU through the CPH. The CPH handles all the other locking
and lighting functions fed via the normal plipper keyfob jobby independent
of the transponder chip in the key. Silly question, have you checked the
chip hasn't gone awol from the swivel of the keyblade...

wheeler · Post by **wheeler** » 04 Jul 2011, 23:46

Although the imobiliser & the remote central locking are both managed by the CPH both systems work completely independant of each other. The remote plip has nothing to do with the disarming of the imobiliser. You can use a plain non remote key to start the car.
Are you saying you lexia wont talk to the injection ecu at all ? Even if the key wasnt recognised & the ECU was 'locked' Lexia should still talk to it.
If lexia wont talk to the injection ECU & assuming there is no fault with your lexia/diag socket then either the injection ECU is faulty (unlikely) or the ECU has lost a live feed or earth. I'd get Jim to post up the injection system wiring diagram & check the live feeds & earths at the ECU.

Post by **CitroJim** » 05 Jul 2011, 06:39

I'll get the diagrams up Mike but it'll not be just yet as I have other activities taking all my time at the moment

superloopy · Post by **superloopy** » 05 Jul 2011, 20:12

Thanks for all the info chaps

Can i ask a really stupid question (or two) ... when we're talking about 'the transponder' do we mean the chip in the key?

And ... if that's the case then where 'should' it live?, Andrew: you asked me to check that' it's still there, but where's 'there'?? I can;'t see anything other than a key blade and solid shoulder to the key, is it inside the plip itself?

Wheeler: when i interrogate the CPH state it shows a '1' against all items except the injection ecu which shows as '0', i interpreted this as being unable to talk to injection ecu due to having no handshake with the key, are you saying that even with a duff key it should still be readable? I did also try and read faults from t the engine ecu (are the two names, engine and injection ecu, the same item?) aside from the CPH dialogue but this also came back as unable to contact the ecu?

Jim: no problem, she's not going anywhere

, in your own time, it's lashing it down up here so doubt i'll get a chance to do much more before the weekend anyways. Thanks for the offer although no doubt i'll have a boatload of questions when it comes to interpreting electrical diagrams as well.

If i make any progress i'll post it up, i'm feeling upbeat now and need to get the passenger airbag out of the way, thats my next job ... big enough for me

Just thought of another one .... while in my lexia session it offerred me an option to initialise one or both ecus. Anyone had to do this cos i'm wondering whether this would be worth a go followed by programming of one (or both). Any pointers on the merits or otherwise of trying?