Xantia 2.0 Excl Auto failure to start

[Mandrake]

The programming information for the CPH and Engine ECU in Citroen Service Box specifically warns that you must get the confidential key correct first time when programming virgin ECU's of either kind as you cannot reprogram it a 2nd time. Same when choosing XM or Xantia on a virgin replacement Hydractive ECU - a one time programming operation.

Try it at your own risk...

Of course even if a Lexia can't reprogram it, one of those ECU chipping companies who can unlock ECU's may have the wherewithal to reset the ECU back to virgin state, but at what expense ?

[stingraynick]

Hi,

Thought I'd post an update....

CPH connectors both disconnected, looked fine with no obvious wiring issues, from the little I could see. Contact cleaner sprayed on both.

Earthing points on the "earth bracket" (?) fitted by the battery looked fine with no corrosion.

Earthing on gearbox cleaned up but to be honest looked fine.

No starting after any the above. Battery disconnect/reboot as well.

Interesting development on the indicator function. As well as the internal courtesy lights flashing in synch with the exterior indicators I spotted the clock, temp indicator, and the speedo and rev counter partly flashing in synch, but also the alarm made a single bleep in time with the flashing as well. Just needed a drum best to blend in as well....

It seems there must be a bad earth somewhere but I've checked those that are either obvious visually or expected like on the gearbox.

Anywhere else I can look?

If not I'm left with pondering getting it towed to a garage the possibibility of spending lots of money and then deciding enough is enough, or spending money on getting a lexia together which might still come to the conclusion the solution is very expensive.

Regards, Nick

[Mandrake]

Does sound like a ground problem!

Do you have the pinouts for the CPH ?

If not let us know and someone will post them for you. You need to measure with a volt meter between a good chassis earth somewhere unpainted on the body and the ground pin(s) on the CPH connector while the key is on. This will tell you if you have a ground problem. You should see less than 0.2v, but if you see significantly more than this, you have a problem.

Also measure between the ground pins and the +12v power feed pins directly on the CPH connector, where you should see very close to full battery voltage.

The main earth point in a Xantia other than for the engine is the metal plate between the battery and left wing. Measure the voltage from the negative battery post to a chassis earth elsewhere on the body with the key on and any accessories that work and/or headlights turned on, make sure its less than 0.2v.

[addo]

The CPH is grounded by a tail to either the central hump near the airbag module or near one of the dashpad side mounts. It's about 3/16 thick, yellow with a green trace.

[addo]

Correction to the earth wire colour.

It's green with yellow trace.

[RichardW]

Have you checked the resistance between the POSITIVE terminal and either the alt or starter? It sounds awfully familiar.....http://www.frenchcarforum.co.uk/forum/v ... =3&t=38273" onclick="window.open(this.href);return false;

[stingraynick]

Hi, thanks for the pointers on testing and no, I don't have details on the pinouts for the CPH connector.

I've had a look through the 'check battery positive lead' thread - could that cause selective failure along the lines I've indicated? The starter turns but a friend helping me on this did comment that he thought ity slightly sluggish. So I will look....

I have to say the starter motor, seemed in an impossible place, unless we were both wrong! It appeared to be on the right (as you lok in the bay) but largely hidden, almost sush that the manifold looked to be in the way...... can't be, but that's what it seemed like.... (series 2 petrol).

Regards, Nick

[stingraynick]

Jim, I've tried 2 PMs re your email address query but they seem to have stuck in the outbox rather than clearing into sent. So I don't think you have either.....?

Regards, Nick

[Ben82]

Jim, I've tried 2 PMs re your email address query but they seem to have stuck in the outbox rather than clearing into sent. So I don't think you have either.....?

Regards, Nick

They'll stick in the outbox until Jim reads them (after which they'll move to sent). Maybe one of the admins can change it to "Sent (unread)" instead of "Outbox"?

[CitroJim]

Jim, I've tried 2 PMs re your email address query but they seem to have stuck in the outbox rather than clearing into sent. So I don't think you have either.....?

Regards, Nick

They'll stick in the outbox until Jim reads them (after which they'll move to sent). Maybe one of the admins can change it to "Sent (unread)" instead of "Outbox"?

Nick, as Ben says....

I've read them both and replied in the affirmative... All is now done on the email front

[stingraynick]

I now understand.....
Nick

[CitroJim]

Nick, it's too late tonight but I must read this thread a lot more closely as the problem you seem to have is usually the result of a wiring fault and is rarely the CPH or anything else.. Unless it's already been suggested, the guilty party is often in the loom that runs under the rad causing a loss of supply to the ECUs. The other classic cause is a duff fusebox in the engine bay...

Do you have full wiring diagrams with harness layouts to help you? If not I can supply all you need in that area - just let me know what you need...

Not tonight though as my day is just about done...

[stingraynick]

Hi Jim,

Thanks for the suggestions but I don't have the wiring diagrams and harness layouts ...

Presumably the loom is accessed from under the car? Any parts need to come away first?

I remember the fuse box weas a major issue on my first V6. Stranded on more than one occasion. The garage sorted that one out at the time. I can see one 13mm holding the rear of the fuse box but couldn't work out how to detach the other invisible fixing - is there a knack or something else to remove first?

Regards, Nick

[stingraynick]

Hello again,

Just preparing for another attempt this weekend....... I've found a handy thread for the bumper removal:
http://www.frenchcarforum.co.uk/forum/v ... =3&t=37434

.....but not for removal of the fuse box in the engine bay.

Can anyone advise? I can see/remove the 13mm holding down at the back of the box but it didn't want to come out and nothing else was obvious.

Regards, Nick

[stingraynick]

Just a bit of an update, and question.....

I've had a look at the wiring loom and in particular the section on the near side corner after the front bumper is removed.

Looks like someone has been there before but, again, nothing obvious. No visible breaks in the wiring and moving the loom around doesn't magically allow the car to restart!

I haven't gone back to the ECUs yet.

Wouldn't mind getting under the fuse box in the engine bay, just to see, but I can't seem to dislodge it. One 13mm accessed from the top behind the box, but it won't move. Can anyone tell me how else it fixes?

Regards, Nick