S1 Xantia V6 - no start, no central locking

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Mandrake
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S1 Xantia V6 - no start, no central locking

Post by Mandrake »

Hi All,

Well the old girl has let me down on the way to work this morning. :( Hopefully you guys have seen this problem before...

My other half went out to get something from the car this morning and told me she couldn't get it locked again....hmm... didn't think much of it until I tried to start the car for work - no dice! #-o

The central locking is not responding at all, when I turn the key on neither of the immobiliser lights comes on, if I try to enter the code I hear it beep but then both red and green lights come on solid together, and they stay on when I remove the key... The engine spins but won't start. Headlights, wipers, dashboard lights are all working - the only other thing that appears to have stopped is the clock. I didn't measure battery voltage but the engine was spinning over at normal speed so I don't think it's that, and I didn't have the time to investigate too much further.

The most obvious conclusion is the fuse for the central locking has blown, but why ? And why so many knock on effects like the immobiliser and engine both not working ?

I don't have any owners manual for this car so I don't know what fuse is what. I have some wiring diagrams for the S2 Xantia on my iPad at home but not S1. Does anyone have a scan of the owners manual fuse pages for a 1997 Series 1 ?

Because the immobiliser lights now won't go out I left the battery disconnected before I left for work...

As a secondary issue, both rear doors won't lock via the buttons - there is movement of the buttons but they don't click or actually lock the doors, so I'm unable to lock the car and have had to leave the car unlocked, fortunately at the house inside a closed gate with no valuables inside. Any ideas on the locking buttons ? They lock and unlock fine via the central locking.
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Re: S1 Xantia V6 - no start, no central locking

Post by superloopy »

Simon ... do the doors all lock with the key from one of the front doors?

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Mandrake
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Re: S1 Xantia V6 - no start, no central locking

Post by Mandrake »

No, the central locking is completely dead.
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Re: S1 Xantia V6 - no start, no central locking

Post by RichardW »

I've got a BOL somewhere, Simon (you can have it when I find it!), but it might be at our storage depot (next door's other house!). IIRC loss of an earth causes both lights on the keypad. CL and Immobiliser function are separate on Mk1 (unlike Mk2), so loss of feed or earth seems most likely - cranking is a separate contact on the ignition switch, so it may be cranking, but there may be no power to the ECU. As to where..... ha ha ha!!! Fuse good place to start looking. I'll try and see if I can find the BOL later and have a look (will have to wait till SWMBO comes back from Yoga, as we are down to one car - C4 is in getting a new clutch. Ouch!).
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Re: S1 Xantia V6 - no start, no central locking

Post by RichardW »

Found this on an old post by Wheeler:

I assume all fuses are ok ? Have you checked that the inertia switch has not been tripped (when the bonnet was slammed down) ?
If both lights are on then the keypad has lost comunication with the ECU, you need to get a pinout of the ECU & check that it's getting all its live feeds & earths. some of the feeds go to the ECU via the double relay under the ECU which if faulty can cause the ECU to loose feeds.
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Re: S1 Xantia V6 - no start, no central locking

Post by electronmirror »

No guarantees with this info taken from BOL for series 1 Xants but not V6 specific. Central locking is Fuse 21 (30A) fusebox by drivers right knee.

hth
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CitroJim
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Re: S1 Xantia V6 - no start, no central locking

Post by CitroJim »

Simon,

Here's the S1 injection Circuit and layouts:

S1 ES9 Injection Circuit

S1 ES9 Injection Harnesses

S1 ES9 Injection Locations

Loss of volts to the Injection ECU is the most likely... The keypad is displaying the symptoms of communications failure with the ECU... If this persists it may need an ELIT or Lexia to reset it...

Check supplies (and earths) to the ECU on-load' as testing with the ECU disconnected can hide a high resistance that can pull the voltage right down when under load..

Hope those diagrams lead to a speedy fix...
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Re: S1 Xantia V6 - no start, no central locking

Post by superloopy »

Just wondering .... are s1 cars equipped with a CPH unit or is that just S2?

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Re: S1 Xantia V6 - no start, no central locking

Post by Mandrake »

Thanks everyone.

I don't suppose you have the wiring diagrams of the Central locking and/or Immobiliser Jim ? I think I do have the engine ECU ones you just posted (or at least their S2 versions which are very close) but I have nothing at all on the central locking, and I suspect that's where the fault lies.
Last edited by Mandrake on 02 Feb 2016, 14:42, edited 1 time in total.
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Re: S1 Xantia V6 - no start, no central locking

Post by Mandrake »

Northerner wrote:Just wondering .... are s1 cars equipped with a CPH unit or is that just S2?
No CPH in a Series 1. There are separate central locking and immobiliser ECU's.
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Re: S1 Xantia V6 - no start, no central locking

Post by CitroJim »

Mandrake wrote:Thanks everyone.

I don't suppose you have the wiring diagrams of the Central locking and/or Immobiliser Jim ?
I do but not immediately specifically for the V6 Simon but here's the S1 'generic' for no particular model... I'd suspect the V6 will be close:

S1 Central Locking

This might help too.. The Alarm circuit

The S2 Injection circuits will be very different due to the different type of immobiliser..

I don't have a keypad circuit immediately handy Simon but can scan one up later...

Shout if there's any others you need Simon..
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Re: S1 Xantia V6 - no start, no central locking

Post by CitroJim »

Simon,

Keypad circuits:

Schematic

Harnesses

Sorry for the scruffiness, pushed for time this evening...

Hope that gives you enough to fix the issue...
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Re: S1 Xantia V6 - no start, no central locking

Post by Mandrake »

Hi Jim,

I spent a while testing tonight and found a few things, but haven't managed to fix it yet. :(

All fuses in both fuse boxes check out OK, so unfortunately it's not something simple like that.

I don't think it's power or grounds to the engine ECU either, despite the seeming lack of communication with the immobiliser - I've checked those at the ECU socket and they seem solid - also I replaced the two ground terminals on the engine block (M4A and M4B) not long after buying the car, so a problem there is unlikely. The grounding of the engine to the body also seems fine. (Anyway if it wasn't, the starter would struggle, and it doesn't)

I thought about trying to query the engine ECU with the Lexia but I remembered that you cannot talk to the engine ECU at all until it has been unlocked by the immobiliser keypad, (it won't even respond) so no use checking that! I also remembered that my Lexia has never been able to talk to the immobiliser keypad, (possibly due to the wiring of the 30 pin adaptor cable) so I don't think I'm going to get any help from the Lexia...

What I have noticed is that the central locking, clock and radio are all not working. The alarm seems to be partially working because when I reconnect the battery the blinkers flash twice, however the alarm doesn't go off as it normally would after removing the battery.

At one point in my fiddling the car sprang into life - I think it was after I slammed the bonnet shut. I noticed that the alarm activated as if the battery had just been reconnected (blinkers flashing constantly - no horn because my alarm horn has never worked) and the immobiliser showed just the red light instead of red and green and the clock had started working - I tried keying in the code and starting the engine and it started and ran perfectly while the alarm continued to flash the blinkers...

Realising that the only way to reset the alarm was to lock and unlock the doors with the fob I switched the engine off and pressed the lock button - there was no sound of door locks activating, and as soon as I pressed the lock button the clock which had previously started working faded out again. Sure enough, I was unable to start the engine again and the immobiliser was back to both lights on.

So despite the immobiliser communication problem it seems like the root cause of the problem may be the power or ground supplies to the central locking system - and apparently the radio and clock share either power or a common ground point with the central locking. And somehow this is indirectly affecting the immobiliser. (There is a connection between the central locking drivers door switch and immobiliser)

Another thing I've noticed is the red LED on the dashboard that is part of the alarm (?) that normally comes on solid with the key and flashes with the key off is not coming on with the key and then a while after the key is turned off it starts flashing very faintly also suggesting a power problem to the alarm as well...

I think to fix this problem I need to find out where the supply and earth connections for the central locking come from, and whether they are shared with the radio, clock and immobiliser...

So is there any chance of the wiring diagrams for the radio, clock, and the central locking ? I need to find out the physical location of any shared earth returns and/or shared power feeds...

Edit: you already posted the central locking and alarm circuit diagrams and I can see there are a number of earth points shared between them, but you didn't post the diagrams that show the physical location of the earths, which I would need to actually find where they are. :-D
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Re: S1 Xantia V6 - no start, no central locking

Post by RichardW »

An oddity indeed Simon! Loose / broken wire somewhere...best of luck with finding it!

BOL is not here, must be up the road, I'll try and have a look tomorrow
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Re: S1 Xantia V6 - no start, no central locking

Post by CitroJim »

Simon, I'm sorry I'm really busy today and will have very little time but will try to get the diagrams you need as soon as I can.. Sorry, please don't hold your breath...

I can tell you the clock return goes right back through the interconnect and back to the main earthing plate in the engine bay...

I'll wager you have a duff splice in the loom that runs under the rad...