xantia - immobilizer issue *fixed*

This is the place for all your Diagnostic related questions or advice.

Moderator: RichardW

Dom_81
Posts: 41
Joined: 13 Jan 2017, 09:08
x 4

xantia - immobilizer issue *fixed*

Post by Dom_81 »

just wondered if anyone might have any insight on a wierd issue I'm having with my xantia HDI 110.

auxiliary belt came off due to broken tensioner pulley. That was repaired and car was driving perfectly for a couple days. Then was driving on and off throughout the day, went out in the evening and the car wouldn't start. RAC guy says codes were showing for low fuel-pressure. Garage replace high-pressure pump and long overdue cambelt at the same time. Now the car wont start and is showing immobilizer fault.
Now they are saying the pump needs to be coded to the ECU, or possibly the antenna on the key fob faulty. Does any of this sound like it makes any sense!?

Thanks for any input.
Dom
Last edited by Dom_81 on 24 Jan 2021, 21:46, edited 1 time in total.

petarc1971
Posts: 57
Joined: 01 Mar 2019, 20:50
x 9

Re: xantia - immobilizer issue

Post by petarc1971 »

I don't think the pump is coded.

Dom_81
Posts: 41
Joined: 13 Jan 2017, 09:08
x 4

Re: xantia - immobilizer issue

Post by Dom_81 »

Thanks, I didnt think it would be!

wheeler
Posts: 4649
Joined: 21 Sep 2002, 19:07
x 212

Re: xantia - immobilizer issue

Post by wheeler »

100% the pump doesn’t need coded.
Have you tried the spare key?
Checked ALL the fuses?
Checked the inertia switch has not been tripped?

Dom_81
Posts: 41
Joined: 13 Jan 2017, 09:08
x 4

Re: xantia - immobilizer issue

Post by Dom_81 »

Great, good to know.
There is no spare key, car was supplied with only one key.... by the same garage carrying out the repairs. The garage is closed now till the new year, when they reopen ill be sure to ask if they checked these things. Im just wondering if the cause of the low fuel pressue codes came from the same source as this immobilizer fault and maybe the pump itself was fine and didn't need replacing.
They did wonder if the key was the issue..could that be eliminated as an option if central locking is still working? (Which I'm not sure if it is or not, certainly was working before car was towed)

petarc1971
Posts: 57
Joined: 01 Mar 2019, 20:50
x 9

Re: xantia - immobilizer issue

Post by petarc1971 »

When the high pressure pump was replaced did the other pump come with a regulator or was it put in from an old pump? The problem may be the fuel pressure sensor which has poor readings and does not allow the ecu to start.

wheeler
Posts: 4649
Joined: 21 Sep 2002, 19:07
x 212

Re: xantia - immobilizer issue

Post by wheeler »

Just to confirm, when you switch the ignition on the orange key light on the dash flashes rapidly & you get a beeping sound? If this is the case is this a new issue only after replacement of the HP pump?
A flashing immobiliser light can mean that the key is not being detected but can also mean that the ECU is not being powered up or that the ECU is not talking to the CPH (the unit that controls the immobiliser function).
Is the low pressure fuel pump in the tank operating?

Dom_81
Posts: 41
Joined: 13 Jan 2017, 09:08
x 4

Re: xantia - immobilizer issue

Post by Dom_81 »

petarc1971 wrote:
26 Dec 2020, 12:14
When the high pressure pump was replaced did the other pump come with a regulator or was it put in from an old pump? The problem may be the fuel pressure sensor which has poor readings and does not allow the ecu to start.
Not sure on that, I'll ask the garage when I speak to them today. They just said the low fuel pressure readings are gone but are now getting immobilizer code instead. Now the garage is open again I'll see if the are able to be more specific.

Dom_81
Posts: 41
Joined: 13 Jan 2017, 09:08
x 4

Re: xantia - immobilizer issue

Post by Dom_81 »

wheeler wrote:
27 Dec 2020, 10:15
Just to confirm, when you switch the ignition on the orange key light on the dash flashes rapidly & you get a beeping sound? If this is the case is this a new issue only after replacement of the HP pump?
A flashing immobiliser light can mean that the key is not being detected but can also mean that the ECU is not being powered up or that the ECU is not talking to the CPH (the unit that controls the immobiliser function).
Is the low pressure fuel pump in the tank operating?
Yes I'm pretty sure the low pressure pump is operating, its nearly new and I can hear it priming and picking up fuel. Now the new pump is fitted the low pressure fault code is gone but is now showing an ECU issue.
Ill ask about the ECU light and if its accompanied by a sound too.. ive not had access to the car since it got towed so I've not been able to play around and experiment.

wheeler
Posts: 4649
Joined: 21 Sep 2002, 19:07
x 212

Re: xantia - immobilizer issue

Post by wheeler »

Dom_81 wrote:
01 Jan 2021, 10:57
Is the low pressure fuel pump in the tank operating?
Ill ask about the ECU light and if its accompanied by a sound too..
[/quote]
Not the ECU light, the key light.

Dom_81
Posts: 41
Joined: 13 Jan 2017, 09:08
x 4

Re: xantia - immobilizer issue

Post by Dom_81 »

Do some fobs have a light? Or do you mean a corresponding light inside the car? Mine doesn't have a light on the fob.
But the car is now running.. apparently the pump really did need to be coded to the ECU.. a car electrician came out and sorted it 🤷‍♂️

Dom_81
Posts: 41
Joined: 13 Jan 2017, 09:08
x 4

Re: xantia - immobilizer issue *fixed*

Post by Dom_81 »

So apparently the high pressure pump really did need to be coded to the ECU, a car electrician went and sorted it. The bill was very reasonable and the garage is trustworthy, I've been going there for at least 10 years and they've got an excellent local reputation.. otherwise I might question it as never heard of such a thing but perhaps as mines a 2001 model ie later than many other xantias, it has a more modern computer? Anyway the car is now purring along and drives like new. Thanks for help and suggestions!

Armidillo
Donor 2020
Posts: 52
Joined: 28 Apr 2020, 02:18
x 13

Re: xantia - immobilizer issue *fixed*

Post by Armidillo »

Just to sort out the ECU vs key light - if there is an immobiliser fault, you see an orange key symbol on the dash that does not disappear (should normally go out quickly). This only happens on SII Xantias with a chip in the key, and is caused by failure of the ECU to recognise the key.

I have a 406 HDi that is not starting and is displaying the immobiliser code, but it's a different problem (fault developed when it was left parked in hot humid conditions for some months). It will fire on aerostart, but that's not a lot of use #-o .

wheeler
Posts: 4649
Joined: 21 Sep 2002, 19:07
x 212

Re: xantia - immobilizer issue *fixed*

Post by wheeler »

Dom_81 wrote:
24 Jan 2021, 21:49
So apparently the high pressure pump really did need to be coded to the ECU, a car electrician went and sorted it.
I can assure you 100% there is no coding of the pump on an HDi Xantia.