In my 3 months or so of chasing my fault I only once came across where the Canbus wiring loom was the actual issue. I read of several instances where the cable was changed (at about £200 ) but failed to sort the issue.
Lucus sorted my issue, although I must say I was a bit sceptical at first - you don't expect a fault to exist where a "respectable" company says there is not a problem.

I have read of many cases where the DEM controller has "leaked water in" which has caused problems. In the USA someone (IPD?) sell a DEM protector to stop water ingress.

IIRC Lucus charges about £30 to check the DEM over, and the recon one I got was about £310. Took about 4 weeks, but I told him I was in no hurry though.

If you wasn't me to put a pressure switch in my AWD R to test it I'll be willing to do it, but a) can't be for about 2-3 weeks as I'm away from home and b) it needs to be mild - my old bones react badly to the cold and I'd have to work outside.

Feel free to use my name/car with Lucas - it might help you.

Cheers

Bob

Bob

Cheers Bob.I need my car so I hope the turn around is quicker for me.Im pretty sure its the Dem after trolling the net for hours.

Right,I took off the haldex unit and checked the oil (all clean) and cleaned the connection and pressure sensor.Cleared the dem-000b code and took it for a drive .The awd worked for about an hour and worked great.Pressure reading was 0MPa at idle then 4 MPa when the awd was demanded .Anyone with vide know if that's right.
Can the wrong oil level cause this code as I think ive a bit too much as when I undo the fill plug fluid dribbles out.

I hate this bloody car!!! Had the Dem sent sent away and it was faulty from an earlier poor rebuild .Replacement Dem coded and fitted....the Dem-000b has gone :) and the pump runs like ive never heard it (because it never had enough voltage I presume from the Dem.
Go to clear the old faults then started car.Pump runs with ignition on but engine off then stops when started...anti skid appears and Dem-0006 WTF is going on!!!
Could I just have low oil pressure I.e low oil level? Really am at my wits end with this car.

Its not oil level as I checked this today and even when the pump is running it shows no pressure at all! Ive just swapped out the pressure sensor and the solenoid above it to no avail...God knows what is going on.

Well after 3 refurbed Dems the problem seems to be fixed!!! Not wanting to jinx it but I've done 100miles with Awd!
Looks like a software issue was to blame with the Dems and my car.Lukas@volvo diagnostic has been very patient and trusting with me and I hope this is it fixed.Drives so much nicer with 4wd.
Hope this is the end to a year long very expensive problem.

Hi, any chance that you could give an insight as to exactly what the problem was and how you finally bottomed it.

Really pleased that you have done it as it's a lovely looking car.:thumbs_up:

Basically the one thing I didnt replace and ruled out was the Dem as I had it repaired by BBA-Reman. On running out of ideas and faults pointing to it I sent it off to Lukas at Volvo Diagnostic.On opening the unit it was found to have been very poorly repaired .Because the unit was not fixed correctly the can communication was far too slow and their was water damage due to poor sealing.A refurbed unit was supplied but failed to communicate properly(neither Lukas or I understand why) so another was sent and everything worked perfectly.Really annoyed that ive spent a large amount of money chasing the problem.

Been away from this section of the forum for a while - missed out on your problems, but glad that you have finally got them sorted.
It would appear that your issue was exactly like mine - a failed DEM controller which was supposedly BBA repaired but NOT. Your issue then compounded by problems with Lucas's initial unit.
Happy that you have got the car running right. I've not stopped smiling since my R was fixed.

Cheers
Bob

Cheers Bob,the xc drives so much nicer now.No torque steer ,wheel spinning etc