Xantia Key Problem

[Garfie]

Xantia Key Problem
1998 R reg Xantia LX 1.9L Turbo Diesel. 145k miles.
The later model without the keypad.
Hello  Citroen owners. I'm new on this forum. (But have studied your posts closely.)
Would greatly appreciate any thoughts you may have on my Xantia problem. - Dashboard key light flashed briefly on starting several times the preceding month before finally giving up. (Luckily when on front drive).  Now, after switch on, all dashboard lights glow (except glowplug light and engine management which glows dimly) and key light flashes for thirty seconds with audible sound, after which, silence and totally immobilised.  . (All three keys tried). My 'Non Lexia OBD2 Code Readers' can't communicate. However, everything else works but interestingly the transponder key aerial (Texton 9627723180) notices key brought close when door is open. (But does this mean it's OK?)
Initial thoughts are - key aerial and CPH active so fault may lie elsewhere with wiring, fuses and relays or maybe unlikely even the injection ECU.
Actions taken so far:-
Checked the multi earth plate connections and all fuses and relays - fine, except glow plug relay (circuit for this according to Haines is separate from the other wiring anyway)
Unplugged cleaned and replugged IC02 & IC02A. (Inner wings) and CPH plugs (behind glove compartment  above heater box)
Tried leaving battery disconnected for several days. No change.
(Not able to remote lock, as remote feature on key fobs have not been working for 10 years.)
Voltages on 35 pin Bosch ECU (0 281 001 262) show zero with ignition off, but switched on, nominally 12v on pins 11, 13, 28, 29,  and 1.286v on pins 14, 15, 16, 32 and 33.
Final thoughts. Wiring, relays and connectors look good but is it possible the aerial  although appearing active is unable to pass on the key number to the CPH when requested?
Or is it the Grim Reaper time in the form of a failed injection CPU?
Finally, would a Lexia be able to point to this problem?
Good clean car with most costly parts replaced and yet rendered totally useless by a now unwanted immobilisation feature.

[Hell Razor5543]

Hi Garfie, and welcome to the Forum,

It is normal (assuming no problems) for that key light to come on briefly when you turn on the ignition (blink and you will miss it). Again, assuming no other problems, if the car does nor recognise the key that light will remain on. You are going to need a Lexia session to see what is going on (it will probably help, but NOT definitely). Don't spend any money on the Xantia until it has had a Lexia look at it. There are members who have Lexias who are willing to help out. Here is that list;

http://www.frenchcarforum.co.uk/forum/v ... 19&t=29178

[Garfie]

Hello Hell Razor. Many thanks for your reply. Yes, having run out of ideas I think giving a lexia a try is worth it before phoning a scrappie. I see there are a couple of lexia owners within a few miles. Perhaps one of them would be able to help. Do you think it would be acceptable for me to approach them direct, or should I wait and see if I get a further response to my post? Not sure of the etiquette of the forum, as I am a newbie.

[BenC5HDi]

Just send them a polite message . We all help out when we can or we wouldn't add our names to the list.

Just don't ask me as my Lexia is broken!

Sent from my SM-N9005 using Tapatalk

[wheeler]

The fact that the EML & glowplug lights are not coming on/glowing dimly suggests to me that the injection ECU is not powered up properly. The key light will flash if the ECU looses communication with the CPH. My bet here is that Lexia wont even communicate with it either, you really need an injection system wiring diagram to check all the supplies & earths to the Injection ECU. Try removing & cleaning the main gearbox housing earth. Have you checked the inertia switch hasn't tripped ?

[wheeler]

Just had a quick look at a diagram (from autodata not original citroen). It shows pins 17, 18, 34 & 35 should be earths.
Pins 16 & 33 should be switched 12v lives (via the double relay)

[Herrsuit]

Just send them a polite message . We all help out when we can or we wouldn't add our names to the list.

Just don't ask me as my Lexia is broken!

Sent from my SM-N9005 using Tapatalk

Hi BenC5HDi Thanks for that. I get the general idea now.

Sent from my M8 pro using Tapatalk

[Herrsuit]

Just had a quick look at a diagram (from autodata not original citroen). It shows pins 17, 18, 34 & 35 should be earths.
Pins 16 & 33 should be switched 12v lives (via the double relay)

Hi Wheeler. Thank you for your thoughts on this. What you suggest makes sense. It would fit in with the intermittent key warning prior to finally becoming permanent. Happily driving wife's Toyota at the moment and we now only need one car, so no great rush. I will have a good look while the fine weather is with us. Never been able to locate the exact ECU wiring for this car which would have helped.

Sent from my M8 pro using Tapatalk

[Garfie]

Hi Wheeler, I luckily found the specific wiring and harness diagrams for this car posted by Citrojim. (Many thanks Citrojim) . Following on with your suggestion, I then checked the ECU plug again and confirm that pins 17, 18, 34 & 35 are indeed earths. Also pins 16 & 33, which are fed from the relay, are not showing a live, as you and the wiring diagram indicates they should, since the relays, although functioning OK, are not in turn receiving and passing on lives fed from the engine fusebox BF01 fuse F7. According to the wiring diagram, the  feed wire from F7 (BM07 ) passes across the front of the car to the ECU box through loom 10PR and at some point changes at a splice (EM07) into BM07A which continues to IC02.  At IC02 it emerges as 3 wires from the plug , called BM07D, E & F which connect to the double relay in the ECU box. (Contactor pins 8, 11 & 15). Found fuse F7 to be live and a single green wire  leaves it underneath and goes into a loom. I stabbed through the insulation with a pin and found it to also be live, so the connector plug seems OK. Working the other way, I  verified continuity from the ECU as far back as IC02, so there must be an interruption somewhere in the loom. I suspect the splice EM07, but to check it I need to establish its location and accessibility. A drawing or table describing its location is needed I think.
Sorry this so long winded, as I'm trying to clarify my own thinking as much as it might help someone else in the future with a similar problem. (If I'm correct, that is.)
(Just a thought, I could try a fused hot wire from the battery to say BM07D, E & F (simultaneously but separately because of amperage concerns)  and see if it produces anything.)

[Garfie]

Well, well, Bingo! That worked. It was indeed the BM07/BM07A wire from Fuse F7, possibly at splice EB07 or back of IC02/IC02A.  Up and running again. (Startled by it starting first throw after eight months standing).  Many thanks  to you guys for pointing me in the right direction. Noticed the corrugated conduits shatter when just touched, so rather than mess with the 10PR loom below the radiator, I think I'll make a permanent job of this (even if I find the original break) by running it neatly and accessible in conduit at high level, . Also, as a precaution, splice these thinner 3 wires BM07D,E & F to it, so as not to have just one receiving the current.   (I notice on wiring diagrams for other models, BF01 - fuse F2 might be used. In which case the splice and wires concerned are EB02, BM02, BM02A,B,C.... etc, and follow a similar pattern, but with an added connection to an ECU with maybe 55 or more terminals).
Finally, I wonder if there are any more dodgy splices in that loom under the radiator?
(In all the joints in all the world, it had to be this one! Casablanca?)

[Hell Razor5543]

Yay! Well done.

[Mandrake]

Glad you got it sorted! Sounds very similar to the failure I had here:

http://www.frenchcarforum.co.uk/forum/v ... =3&t=54226

It looks like this under radiator wiring loom is becoming a real nemesis on Xantia's of a certain age.

In my case the faulty section of wire would be nearly inaccessible without removing the bumper and then you have to identify the wire...

In my case I was able to take an alternate feed from the ignition key switch feed and link it to the back of the drivers foot well fuse box! A lot of work but it ended up to be a nice permanent fix.

[Garfie]

Hi Simon. Just read through your similar problem. What a marathon investigation. Well done! Yes, this 10PR loom is somewhat worrying. Running it under the rad and highly inaccessible and then throw in a few splices!!! Whatever were they thinking! I've bought some 6mm corrugated conduit and am waiting for some 1.5 sq mm wire to arrive. I am looking to run the wire round the back of the engine bay with clips or tie wraps. Not sure just yet. Having read your problem I might include another wire as spare and leave the protruding ends coiled. I've been to Jersey on the ferry a couple of times with this car and now can envisage the scenario "This is the Captain speaking, we are shortly to arrive, would everyone please return to their cars". You are at the front of the queue and the key warning light starts flashing. Next thing, lots of tooting and the " serves you right for driving a banger" looks. Nightmare.
Garth

[Garfie]

Just to conclude on this problem. I decided instead to run the bypass from the ecu box across the front above the radiator and mainly hidden under the front plate. I used 6mm conduit which was a bit of a mistake for adding a couple of spare cables. 10mm would have been better. I passed the conduit through a grommeted hole cut in the front side of the ecu box and left a loop to allow the ecu to be withdrawn before splicing onto wires BM07D,E & F all joined together as one splice. Rebound the wires with just electrical tape but might get some intumescent tape to make a better job of it. Took the other end of the conduit down to battery tray level along under the glow plug relay and IC02A and brought it up through a gap into the underside of BF01 fuse box. Spliced onto the green wire BM07 which leaves the underside of fuse F7. Everything works fine. Even the glow plug relay I thought was defective. Originally led astray by Haines diagram which does not show clearly that the relay is under ecu control after all - on pin 4. I spent time taking the relay apart and replacing some of the more usual suspect components all unnecessarily. Took the car for a quick try and was immediately reminded of what a luxury drive this car offers.
Thanks again guys for your input.

[Hell Razor5543]

Well done.