DEM Repairs
 

Hi,
My Volvo XC90 suffered problems a few weeks ago in that it began to display the message "Brake Fault stop safely". This changed to "Anti Skid Service Required". I could clear this with turning the ignition off and then on again. Initially I thought it was the BCM, but after testing loads of things and getting nowhere, I was forced to admit defeat and take my car to Volvo for testing. Dont know why I didnt do that first, but I'm now aware the DEM is faulty and is off the network when it was plugged into the Volvo diagnotic system. The wiring has been checked and everything is fine up until the point it gets to the DEM. My problem is the price of a new unit; £1480. Does anybody know anywhere these untis can get repaired. I cant personally understand why they are so expensive, do they have platinum internal parts, or diamonds maybe that I can remove and sell on to fund the price of a new unit. Sorry for my sarcasm Mr Volvo, but it does seem a tad expensive for a metal box no bigger than a packet of cigarettes.

Hi

If you are sure its a module fault, then try these guys:

http://www.bba-reman.com/uk/index.aspx

Normally, they can fix your own part (at a component level) or sell you a new or exchange unit.

You may need it coded if its a new/replacement part, so you would be back at the dealer.

They know what they are doing... give them a call!

David

BBA did a top job with the DEM. The entire job including the postage cost £128, a big difference from £1480 for a new one..................and the software, labour etc etc. These guys are well worth a try

DEM just gone on my XC 90
 

Hello - I'm new to the forum, found it by searching the net for XC90 DEM problems. I have a 2004 XC 90 Diesel D5 AWD. The AWD is not working as I clearly had no power to the back wheels in the recent snow here in Dublin. I took it to the Dealer and they linked up to the diagnostics and got 'DEM 000b - Oil Pressure incorrect value'. Their manuals tell them to replace the DEM in these situations. I take it that this is correct ?. They quoted me over 2K euro to replace the DEM. Seeing the mails on BBA and this part look great, but while I am technical and love a challenge, I have not messed around with the internals of the Volvo yet so I have a few questions if someone could help (another punter not having to shell out 2k unnecessarily !):

-Where in the engine is the DEM located. Do I access from the top or underneath the car ?

-Is it purely an elecronic part i.e. just pull out wiring connectors no oil leaks involved etc. ?

-I assume you cannot drive it while the DEM (even if faulty) is out ?


Thanks,

Terry.

I'm not so sure they have advised you correctly. I must confess I'm not a mechanic, but I managed to diagnose my XC90. The DEM has a pressure sensor which is sandwiched between the rear diff and the DEM itself, it could be this. The sensor I dont beleive is that expensive. Or it could be the DEM itself. What I found out that any apparent problem with Volvo's could be a multitude of things. But I think you did the right thing by taking it into Volvo for a diagnostic and I dont think I would be shelling out 2000 Euros on a new DEM. The DEM is underneath the car and is bolted to the rear diff by two 6mm bolts. It is immediately above the exhaust if that helps. It is a silver metal box which is packed with electronic components. If you remove the plastic multiplug and the two 6mm bolts it will pull off. Unfortunately for me, one of the bolts snapped when I tried to take it out, so I had to drill it which made it a harder job than it should have been. When it comes off, you will see the pressure sensor. There will be a little oil as the pressure sensor slides out, but its not much (about 10th of a teaspoon). When mine was off the car, there was a small amount of leakage, but its not much at all. It seems to leak out over a period of days, and it probable amount to about half a teaspoon over a week period. I would imagine you could plug the hole with something if you really wanted to. I did not use my car whilst the DEM was off. I thought that if I did use the car, the haldex would pump oil out where the pressure sensor should fit. I dont know for sure it does, but I just suspect it probably would. I dont know how you would check the pressure sensor, i think if it was me, I would send the DEM off to BBA for checking. If they check it and its fine, they charge something like £40. But if Volvo recommend this is changed with the code you've got, I would do this first. If you want a picture of the DEM and sensor, send me your email address and I will send you some pics. Good luck with the repair.

Picture of the DEM circled in red:

http://i821.photobucket.com/albums/z...onreardiff.jpg

Thanks Gasc2188/ascona-400 - Last night I noticed the mass of complaints under the thread XC 90 4WD problems. I have gone back to Volvo with this thead and its information asking them to fix the problem. It's the same thing from my point of view - another XC 90 from 03/04/05 whose AWD/4WD has packed in. I will keep you informed how I get on.

Terry, i thought the dealers here in the states were a bunch of bloody ******s. seems like you guys got a bunch there too. first picture is the part and the part number. $100 USD the second picture is a VOLVO tech notes, look at the DEM 000B code, the last one. they a bunch of liars. Bring this print out to the dealer and see what they got to say now. this is a easy job to do. if you choose to do it yourself, get the haldex fluid too and do a fluid change while you are in there. i know the notes say 06-07, its the same darn thing for 03+. Good luck and please stick it to them and report back!!
http://i216.photobucket.com/albums/c...IMAG0166-2.jpg
http://i216.photobucket.com/albums/c...dexTNN-2-2.jpg

Thanks gshadow325,

Your analysis is inline with gasc2188's thinking also. Volvo came back to me locally (in Ireland) today and gave me a PFO (please ***! off). I will next go to the Customer Services Manager locally and failing that go to Volvo UK/the UK dealer as I bought the car off Mills in the UK. All that failing I will start off with the small back street mechanic down the road that I know well and have him replace the sensor, failing that have him take out the DEM and send to BBA for testing/fixing. Sound like a plan ?.
I have a strange feeling given all of the above that there still could be a sleeve/splines issue like the main thread 'http://www.volvoforums.org.uk/showthread.php?t=66098'.
Anyway I am shocked that they would not try the sensor first. I even mentioned it to them on going in. I hope that they are at least being upfront with me that they did get 000B on the diagnostic. I've seen on another post that you can check the status of modules by holding down the read button on the end of the indicator lever and turning on/off the rear fog light twice. I will try this to confirm the DTC.

Thanks,

Terry.

this pressure sensor is incredibly easy to replace with common tools. its just a allen head wrench. the dem connectors and then slide it off, it actually falls off. then just replace it. i dont think the dem is bad yet. change the sensor and while you are at it change the haldex fluid too.