
Simon's new Xantia V6 and Leaf blog
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Re: Simon's new Xantia V6 blog
Thanks Steve. Eight pages to explain the immobiliser ? sheesh ! 

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- NOT Alistair or Simon
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Re: Simon's new Xantia V6 blog
Think yourself lucky it is only eight!
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- A very naughty boy
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Re: Simon's new Xantia V6 blog
Simon, the V6 is certainly happy to have the keypad disconnected. Do it whilst the engine is running and it'll not be needed again. Do make a note of the last code as if you ever want to reconnect it you'll need it.
To reconnect a pad without knowing the code is fatal.
Make a note of it in marker pen on the ECU...
To reconnect a pad without knowing the code is fatal.
Make a note of it in marker pen on the ECU...
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Re: Simon's new Xantia V6 blog
Thanks Jim, but is the code stored in the immobiliser or the engine ECU ? If you were to swap immobilisers between two cars (not that I plan to) would the code stay with the same car or would it go with the immobiliser unit ? Just trying to understand how it functions...
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- A very naughty boy
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Re: Simon's new Xantia V6 blog
The code is stored in the ECU Simon. I've proved this is the case on both diesel and petrol versions
The keypad does not remember codes in any meaningful way.
The immobiliser functions are all built into the ECU on an S1, unlike the S2. The keypad communicates with the ECU over a serial communications link.
The only ECU that cannot have a keypad disconnect is the TCT/Activa one. Don't know why...

The immobiliser functions are all built into the ECU on an S1, unlike the S2. The keypad communicates with the ECU over a serial communications link.
The only ECU that cannot have a keypad disconnect is the TCT/Activa one. Don't know why...
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Re: Simon's new Xantia V6 blog
So when you enter the code the keypad unit just sends the code to the engine ECU which unlocks, and then some period of time after you turn off the key the keypad unit sends a "re lock" command to the ECU ?
So by unplugging it while running it never gets a chance to send the "re lock" command so the ECU stays unlocked...cunning
So by unplugging it while running it never gets a chance to send the "re lock" command so the ECU stays unlocked...cunning

Re: Simon's new Xantia V6 blog
I know for a fact it's in the ECU as I've swapped keypads between cars in the past. Disabling it is easy, and quite honestly, getting round it is hardly the work of a genius, especially on a TD!Mandrake wrote:Thanks Jim, but is the code stored in the immobiliser or the engine ECU ? .
Re: Simon's new Xantia V6 blog
Got it in one Simon.Mandrake wrote:So when you enter the code the keypad unit just sends the code to the engine ECU which unlocks, and then some period of time after you turn off the key the keypad unit sends a "re lock" command to the ECU ?
So by unplugging it while running it never gets a chance to send the "re lock" command so the ECU stays unlocked...cunning
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Re: Simon's new Xantia V6 blog
I might unplug mine then, although leave it physically in place for now since I don't have an oddments tray to fit. I really find remembering to enter the code a pain, especially when you can't see the buttons past the gear lever without leaning right over...(brilliant design there, the gear lever obscures both the keypad in park AND the sport mode LED in drive...
)
It might be in good nick and be low mileage, but nobody is going to steal a 17 year old Xantia!

It might be in good nick and be low mileage, but nobody is going to steal a 17 year old Xantia!
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- A very naughty boy
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Re: Simon's new Xantia V6 blog
Don't be so sure. I had a dream last night that someone stole my Activa and replaced it with one in terrible condition; full of rust, water leaks and odd wheels...Mandrake wrote: It might be in good nick and be low mileage, but nobody is going to steal a 17 year old Xantia!
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Re: Simon's new Xantia V6 blog
Correct me if I am wrong, but I read somewhere that unplugging the keypad works as long as you don't disconnect the battery...
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Re: Simon's new Xantia V6 blog
As promised......










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Re: Simon's new Xantia V6 blog
Jim, you think the TCT ecu could be unlocked in the same way some pugs are unlocked by just disconnecting the ecu while the engine is running? Then disconnect the keypad turn it all off, plug the ecu back in and unlocked ecu is done? I'm sure this is the process used on 306 gti's...
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Re: Simon's new Xantia V6 blog
You'd be surprised what the parts of one could be worth abroad, lost cars are stolen for parts these days as they are much easier to move on.
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Re: Simon's new Xantia V6 blog
You're right Xantos and it works on all but a TCT Activa for reasons nobody knows.xantos wrote:Correct me if I am wrong, but I read somewhere that unplugging the keypad works as long as you don't disconnect the battery...
Will, one of the ECU specialists can unlock one at a cost...