Xantia immobiliser / CPH fault ?

[Mandrake]

Hi All,

Two times recently I've had what looks possibly like an immobiliser problem - after having driven and stopped the car for 2-3 minutes, upon starting the car the orange key warning light on the dashboard has flashed for about 30 seconds, along with a continuous warning tone. The odd thing though is that the engine has actually started, its not refusing to start. (yet...)

Checking on the Lexia shows the following faults logged on the CPH:



Faulty key (identity not received) in both "permanent" and "intermittent" varients is a code that always comes back after a period of time and has done so ever since I've had a Lexia, so I'm not sure that it's relevant to the issue at hand, Locking failure caused by the left door locking button is not one I've seen before, but possibly not relevant either. (Out of interest has anyone noticed that the CPH reverses left and right front doors, at least on RHD Xantia's ?)

ECU error: unlocking error is I assume related to the warning light and sound... has anyone come across this before ? Although it hasn't stopped the car from starting yet and it has only happened twice, I don't want to be stuck somewhere unable to start the car because the immobilising system has decided to throw its toys out of the pram..

This is a Series 2 1998 V6 so there is no keypad, just the CPH unlocking the engine ECU when the code from the key transponder is recognized.

[Mandrake]

Bump ?

Here's a video where I caught the last 5 seconds of what lasted for about 30 seconds:



What I don't understand is why the engine started anyway despite the warning... has anyone experienced this before ?

I'm a bit nervous about getting stuck somewhere unable to start the car as we'll be using the car extensively to move house over the next month or so...now would be a bad time for it to let me down.

[Ben82]

Probably totally way off the mark here, but since so far there's been no other suggestions ... Xantia equivalent of the C5's "Engine Immobiliser Fault" when the car battery is on its way out?
It exhibits the same symptoms (bar the lexia stuff), engine starts even though the dash reports the fault, albeit the C5 one is brief, but could be down to the way the xantia reports it.

[Mandrake]

Battery is something I hadn't thought of, although I haven't had any other symptoms of a sick battery, and the battery is less than a year and a half old as lexi fitted a new one in his short tenure of the car...

I wonder if the transponder antenna on the ignition lock needs replacing, maybe its a bit marginal as any time I check the CPH for faults after any length of time it always shows multiple fresh instances (20-30 in a month is typical) of permanent or temporary "Faulty Key (identity not received)" despite never (until a couple of weeks ago) giving any actual dashboard warnings, and never failing to start.

Does anyone else see seemingly spurious faults logged in their CPH that keep coming back after clearing but don't seem to cause any visible problems ?

"Engine ecu: unlocking error" is new though, I've never seen that before until after the first time I had the 30 second flash, which was only a couple of weeks before the second time it happened, so something is afoot...

[spider]

Its possible it was unable to lock it for some reason, faulty CPH possibly (unlikely and a pain I think on the Xantia as it lives above the glovebox) If its any consolation mine actually shows:

ECU Locked: 0
ECU Unlocked: 0

Although it would not matter for mine if it did lock itself as I don't have an aerial connected (I'll spare you the details)

Regarding your situation: The lack of ID being received may point to a failing transponder aerial. If you have another key please try that first to see if its any better.

On some models the wiring inside the transponder aerial unit could slightly tarnish (the coil wires) causing odd intermittent starting issues. I'm not sure how relevant that is to your case but I think its worth knowing about.

[Sid_the_Squid]

With my Current Xantia HDi Occasionally I get an authentication fail, with the light on and the beeping, but my engine wont start... simply turning off and on and waiting until the 'key' light goes out before cranking solves the issue..
I strongly suspect its my dodgy battery which seems to be getting quite weak, I get slow turning over and the needles flipping all around on starting.

So good possibility its the battery, but as you've got a V6, it could be the start of something a bit nastier. check this thread http://www.frenchcarforum.co.uk/forum/v ... =3&t=33930, this as you'll see is something which happened to me when I owned a Xantia V6, whip the front bumper off and apparently its obvious if the wire is gone or not.

[RichardW]

I get slow turning over and the needles flipping all around on starting.

Check the temperature of the +ve terminal a couple of minutes after starting - carefully - my guess is you will find it's too hot too touch! See the sticky thread at the top of the page.

[Xantidote]

Check the temperature of the +ve terminal

And obviously check the earth cables & terminal while you're at it

[Mandrake]

Regarding your situation: The lack of ID being received may point to a failing transponder aerial. If you have another key please try that first to see if its any better.

On some models the wiring inside the transponder aerial unit could slightly tarnish (the coil wires) causing odd intermittent starting issues. I'm not sure how relevant that is to your case but I think its worth knowing about.

I do have a spare key although its only a plain key with no RF transmitter.

So I could clear the faults on the Lexia and try to remember to use only the spare key in the ignition for a few weeks, although I'd still have to carry both around otherwise I can't arm the alarm. I suspect I'll find I get the same intermittent fault codes coming up though, so transponder aerial does seem a likely culprit if it still keeps logging fault codes. Are they expensive or hard to replace ?

[Mandrake]

Simon, take a look at this thread which I started a while ago.

There's a distinct similarity in the CPH faults logged. Let's hope that your wiring harness isn't playing up.

My car is still as yet unfixed (read - broken) as is my Lexia which I did intend using alongwith the harness tester in an attempt to identify the problem.

Unfortunately i'm no mechanic (or auto electrician come to that) and the car will stand no longer than this year before being disposed of unless I can get
my finger out

Funnily enough a Google search turned up your thread so I've already read through your thread cover to cover. I'm sorry to hear it still isn't fixed! What's gone wrong with your Lexia ?

[Mandrake]

With my Current Xantia HDi Occasionally I get an authentication fail, with the light on and the beeping, but my engine wont start... simply turning off and on and waiting until the 'key' light goes out before cranking solves the issue..

Both times its happened to me its not beeping, its a continuous tone for 30 seconds along with the flashing light...yet the engine has started and I've driven away...

I strongly suspect its my dodgy battery which seems to be getting quite weak, I get slow turning over and the needles flipping all around on starting.

So good possibility its the battery, but as you've got a V6, it could be the start of something a bit nastier. check this thread http://www.frenchcarforum.co.uk/forum/v ... =3&t=33930, this as you'll see is something which happened to me when I owned a Xantia V6, whip the front bumper off and apparently its obvious if the wire is gone or not.

Google turned up your thread when I was searching too, so I've read that one already. Not sure if the symptoms are the same but I will keep an eye on it.

[addo]

It does rather sound like a transponder aerial fault. At least it's a sub-£20 part for once.

[KennyW]

Simon,

I have transponder aerial in the garage, I don't think there are any differences between models.

Kenny

[aneesh84]

I have had the same 30 second tone with the key symbol for the past 1 year and the car never failed to start.

Today however it just refuses to start. I dont have a lexia.

Did your car also stop starting after a while Mandrake?

What was the solution?