Xantia Immobiliser Code Help

[protemporum]

Hello, i need help, four days ago i changed the pin code on my 1995 Xantia 2.0 petrol 8 valve. Then i got interrupted, and writing down the new code went completely out of my head!
Yes, now i cannot remember new code!
I have followed the code reset procedure in the owners manual, but of course, without the new code, i cannot return to old code or set a new code!...does all that make sense?
I do hope someone here can help me, or i have a completely immobile Xantia!
Yours, Roger.

[GiveMeABreak]

If yours has the ADC immobiliser Key Pad Entry System, I think it's definitely 'tempus est scriptor'.

According to the documentation I have, the test with diagnostic tools can only determine whether the codes are being sent and received correctly. The actual customer code is still needed to unlock the system.

The ADC on the Petrol Xantia communicates directly with the Engine ECU and if the code is lost, then you will need to have the ECU re-configured:

CAUTION: In the case of losing the code of the coded anti-theft device, the injection ECU has to be modified.

[xantia_v6]

Marc is correct, there is no way for a user to recover or reset a lost code. To recover from this situation, you need to do one of 3 things:

• remember the code that you set
• Obtain an ECU of the correct type with a known code to replace your ECU
• Pay a specialist company to reset or recover your code

I believe that there are 5 techniques that can be used by a specialist to recover/reset the code.

• Connect the ECU to a scanner box that runs through all the possible codes until a match is found (this can take several hours).
• Read the code from the EEROM chip in the ECU
• Read the code from the EEROM chip in the keypad (I don't understand why it keeps a copy, but I believe that it does)
• Reprogram the EEROM chip in the ECU back to its factory default values
• Reprogram the ECU EEROM or Flash memory so that the immobiliser code is no longer required

The last of these is probably the most common fix.

[protemporum]

Hello GiveMeABreak and xantia v6,
thankyou for your prompt replies. I have been very desperate for a cure for the problem of me being an IDIOT, so have made several enquiries with old friends in the motor trade. An auto-electrician says he knows a man in Northhampton who can reset the ECU but there will be no immoboliser key pad function. So i am presuming (a very dangerous thing to do),item 5 on your list xantia v6.
I am an old IDIOT and so have no idea what a ADC immoboliser is. So i am a little concerned about your caution note GiveMeABreak.
My Xantia has a key pad just in front of the gear lever, does this mean i will need the injection ECU modifying?
This may all seem to be a waste of time and money for such an old car, but i have just had it MOT tested, now has 13 months ticket, it is taxed and insured (that's a bit of a novelty in this day and age) and i have just bought a full set of 6 spheres, it runs like a dream and returns almost 40 miles per gallon. It was one year old when i bought it and 178600 miles later it may be the last car that an old fool like me will own.
Thakyou for your time. Roger.

[GiveMeABreak]

I am an old IDIOT and so have no idea what a ADC immoboliser is. So i am a little concerned about your caution note GiveMeABreak.

ADC is just a French abbreviation for 'antidémarrage à code' or 'Immobiliser Code'

My Xantia has a key pad just in front of the gear lever, does this mean i will need the injection ECU modifying?

Yes, because you have the Petrol vehicle so the Injection ECU handles the immobiliser code function as opposed to the Diesel engine that operates on the fuel cut-off side.

This may all seem to be a waste of time and money for such an old car, but i have just had it MOT tested, now has 13 months ticket, it is taxed and insured (that's a bit of a novelty in this day and age) and i have just bought a full set of 6 spheres, it runs like a dream and returns almost 40 miles per gallon. It was one year old when i bought it and 178600 miles later it may be the last car that an old fool like me will own.

The only way to unlock the engine ECU is as Mike has mentioned above - there are several options for you to consider, but I would certainly look into it as she obviously seems worth it to you. It shouldn't take too long to do - some of these people are even mobile.

[xantia_v6]

My first choice would be to find a replacement ecu if you can, but it must come from a Xantia with the same engine type.

[protemporum]

Hello, thankyou GiveMeABreak and xantia v6 for your replies. Darren at D.J. Auto Electrics has unlocked the ECU. Car runs perfectly, starts first turn of the crankshaft, no stalling, 'pinking', runs with no miss fire etcetera. So appears not to need the Injection ECU modified. (Darren assures me that Injection ECU is "Good to Run").
Thankyou all for your help.
(Not sure if i am allowed to mention commercial names, so feel free edit post.)
Roger.

[GiveMeABreak]

That's what we meant in an un-technical sort of way Roger He has probably removed the code. Whether you can now setup a new one or not will depend on what he has actually done - but regardless, you have your car operational again - which is good news.