Xantia immobiliser issue

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zs&tas
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Xantia immobiliser issue

Post by zs&tas » 03 Jul 2019, 18:06

Hi,i have a 96 1.8 8v petrol xantia. Recently i have experienced some strange immobiliser issues. It first started in Sainsbury's car park , jumped in the car , put code in and the green light was already on , it beeped away then would not turn over. I found an earth lead from the coil that has a small black box on the end of it, dangaling, i put it on a stud and the immobiliser went back to normal and the car started. Its happened a few times but ive now got a solid earth on that lead which seemed to fix it untill today , today it wouldnt start untill i played with the central locking and remote , took ten mins of fiddling but got it going again , im wondering what could be up now ? Can i didtch the immobiliser alltogether ? Any advice appreciated. Sorry for the lengthy post , i searched and got lots but not like mine ? :roll:

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xantia_v6
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Re: Xantia immobiliser issue

Post by xantia_v6 » 03 Jul 2019, 18:17

I think that you may be getting confused by some random intermittent behaviour. The immobiliser is built into the engine ECU. The thing you found by the coil is probably a suppressor capacitor and not vital for normal operation.

As far as I am currently aware, on a MK1 Xantia there is no connection between the immobiliser function and the locking or alarm systems.

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Re: Xantia immobiliser issue

Post by xantia_v6 » 03 Jul 2019, 18:38

When it ( currently) will not start, which of the keypad lights are on?

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Re: Xantia immobiliser issue

Post by zs&tas » 03 Jul 2019, 18:39

Hi, thanks for the reply, not looking forward to random faults :(
That coil earth wire definitely helped it start before . I'll have to do some more searching , I've got to take it on holiday soon !
Maybe the ECU connectors need cleaning

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Re: Xantia immobiliser issue

Post by zs&tas » 03 Jul 2019, 18:42

The green light stays on , won't go back to red like normal if I jump out of the car and get back in , it's just throwing a benny lol . I havnt been back to the car since we made it home so I'm hoping it's in workin condition still ! For work in the mornin . I thought I'd do some research before I nosed around .

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Re: Xantia immobiliser issue

Post by white exec » 03 Jul 2019, 18:57

iirc, Having had a green light and normal start, if you switch off the IGN (and maybe getting out of the car without locking it, and getting back in) and turn the IGN on again, keypad light will jump straight to green, without the need to re-input the code. Leave it longer, and you'll get a red, and need the code.

Some of these keypads can also be programmed (see Owner's Handbook) not to to need a code, but showing green (and allowing a start) as soon as the IGN is switched on.

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Re: Xantia immobiliser issue

Post by zs&tas » 03 Jul 2019, 19:16

Oh didn't know I could program it to not be used ,I'll have to look for the manual I'm sure it came with the car thanks !

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Re: Xantia immobiliser issue

Post by xantia_v6 » 03 Jul 2019, 19:42

zs&tas wrote:
03 Jul 2019, 19:16
Oh didn't know I could program it to not be used ,I'll have to look for the manual I'm sure it came with the car thanks !

It depends on the version of immobiliser you have, but you probably don't have the option of disabling it in that manner, and it is extremely unlikely that it would help start your engine.

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Re: Xantia immobiliser issue

Post by zs&tas » 04 Jul 2019, 05:02

Good morning, what a B E A Utiful day , car started fine this morning , unfortunately that means I got to work ok lol . I think when I'm finished fitting the rear discs this weekend I'm going to be looking at some earth's around the car and see what I can find , where is the engines computer on this car ? There is possibly more this story too which might freak you out ;)

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Re: Xantia immobiliser issue

Post by xantia_v6 » 04 Jul 2019, 05:45

The engine ECU is located in the rectangular box behind the RH headlight. There are probably also a couple of big relays in there which may also be suspect in this case.

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Re: Xantia immobiliser issue

Post by zs&tas » 04 Jul 2019, 15:16

Yeah there's a large double size looking relay , might try a new feed to that if I can work out which wire . Is it worth earthing the ECU case , or just find the right wire for that too ?

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Re: Xantia immobiliser issue

Post by zs&tas » 07 Jul 2019, 08:38

Just did the rear discs and pads , had one caliper bolt snap when we looked at it lol . Oh well it's done now ! Cars been starting ok in the cooler temps , also maybe because I leave the ignition on longer before starting . I will stil do some rewiring before the hols though 👍

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Re: Xantia immobiliser issue

Post by zs&tas » 09 Jul 2019, 12:26

IMG_20190709_114105519.jpg
Did some wiring today ;)