2006 XC70 - Christmas :-/ Topic is solved

daandus · Post by **daandus** » 28 May 2020, 17:16

Put it back together, reconnected battery.
No codes. (DEM still connected)
Car started, right away came back brake failure message. Then it stalled.
Tried to start again, crank but not start (that is a first).
Off/on ignition, immobilizer message, wont crank anymore.

daandus · Post by **daandus** » 28 May 2020, 17:17

Mm...... now with big connector loose from Dem, only code i see is 'tail gate open'.
Will idle it for a bit, short drive and then Vida/dice it to see what's what.

May be onto something!

Fyi, connector was super clean by the way.

I will pull DEM fuse and see what it does. May still mess up canbus if it is shorted out or corroded?

daandus · Post by **daandus** » 28 May 2020, 17:47

Okay, succes - maybe.
DEM disconnected - no codes or trouble
DEM connected - brake failure right away - and immobilizer shortly after.
DEM disconnected - no codes or trouble
DEM connected - brake failure right away - and immobilizer shortly after.
DEM disconnected - no codes or trouble

For the record (and other people that may use this info):
I pulled fuse 23 (7.5A) on the cargo compartment and it gave ABS errors right away still. I put fuse back and disconnected the plug from the DEM to ensure it doesn't mess up the canbus.

Post by **vtl** » 28 May 2020, 18:50

I had similar/same symptoms last summer. It was DEM. Here's the broken part:

Hand is not empty =)

Oxidation:

One resistor in the top right corner looked suspicious:

Had it desoldered and inspected: the connecting pad was fully rotten on the side facing the PCB. Replaced it, resealed DEM properly, and it is good since that.

daandus · Post by **daandus** » 28 May 2020, 19:41

Wow!
Something that small - electronics can be fun!
I'm in need of a rebuilt somehow (I won't have the skills to troubleshoot the actual circuit board)
Who do you advise? XemodeX seems good ,but a little steep at $800?
I see all kinds of ads on Ebay for 1/7th of that.... any experiences?
Also XemodeX advises to also do the pump and all. Seems like a lot of fork, pump humms nicely and AWD worked fine before - is it worth the preventive swap?

Thanks again for everyone's help!

Post by **vtl** » 28 May 2020, 20:00

I would advise sourcing a working DEM with the same part number, splitting it up, cleaning PCB with alcohol and resealing it. Make sure you add sealant around connectors as well (but avoiding 3 small holes between them - in my pic I put sealant over one hole). Sealant needs to be high-temp, I've used one left from gas fireplace repair.

Or use any DEM rebuilder and add sealant around connectors yourself.

Also buy or fabricate splash shield like this IPD: it helps a lot.

Haldex pump is good for about 10-12 years. Shortly before death it starts to gulp Amperes, like 3 Amps. Pump current can be read in VIDA.

daandus · Post by **daandus** » 28 May 2020, 20:30

Thanks - good tip!
I understand the part number is very important to match with what you have - does it then NOT need software reload or VIN trouble or anything? I like the idea of fixing one up myself actually...

It all looked very stock underneath however AOC pump was replaced by the dealer in 2014 - so that should go for a bit longer I would hope.
I'm looking around for DEM repairs, UK company advertises for 140 GBP - which is 240 CAD - tempting.

Post by **vtl** » 28 May 2020, 20:44

Software reload is not needed if you match P/N (or get another one that has software for a similar CAN network configuration). Getting same P/N is easier

Used DEM for my model year is around 100 USD on Ebay.

Rvolvos · Post by **Rvolvos** » 29 May 2020, 22:47

I am no expert on this, but I happen to have a 06 XC70 and I experienced once the car going into limp mode, just after driving from a curb. I was able to reset the car with locking and unlocking it 3x times and drive home.
I did not have Vida at the time and got codes P0600, P0700 and P0863 With a generic code reader. I cleaned the contacts of the ecm and Tcm. I noticed the ecm had a lot side to side play, compared to the tcm. I have wedged a tie wrap in the slot to limit the motion. 3 years still running fine.
Maybe it helps you out. Good luck!

daandus · Post by **daandus** » 17 Jun 2020, 11:16

Thanks for all the help!

Finally my DEM came back from rebuild (COVID situation slows down parcel shipping a lot in Canada it seems...)
Also, the rebuild company took a full week for their '2 day turnaround time'.....

Anyhow, $450-ish CAD later www.unitechelectronics.ca replaced a few capacitors and resistors - and the unit seems fine now. Just installed it and took the car for a spin.
AWD works fine (but always did when the car ran), but more importantly: no dash lights and CANBus freakouts.

2006 XC70 - Christmas :-/ Topic is solved

Re: 2006 XC70 - Christmas :-/