DEM-0001 AWD Not Working

[XC70Rider]

After cold start this morning the DEM-0007 didn’t appear.

Four hours later I drove her 5 miles then checked for DTCs. The DEM-0007 did come back but was getting a pressure reading and the AWD was working.

Is it a bad connection coming loose at certain times or the oil pump is starting to randomly fail? Getting a new oil pump delivered on Friday so waiting until then to raise her to check connections and Haldex oil level.

Edit:

I'm leaning more on a bad connection coming loose at times . If the pump was randomly failing then DEM-0006 would appear along with DEM-0007.

[XC70Rider]

DEM-0007 is still randomly appearing at times but AWD still works even if I don't clear the DTC. I can feel the AWD engaging during acceleration or driving uphill. Also getting oil pressure readings on VIDA when the DEM-0007 appears.

I feel it's a bad sensor terminal connection within the DEM.

I'm going to return the $280 new Haldex oil pump and just rebuild the OEM oil pump. When the rebuild kit gets delivered next week I'll remove the driveshaft for the 3rd time so I can remove the oil pump. I'll also open up the DEM and swap connections with the DEM I got at the JY. I'll solder the mechanical connections.

[XC70Rider]

When I hooked up VIDA yesterday I got the DEM-0007 code. I cleared the code then drove her for a mile. The AWD worked and the code never returned. Wouldn't this code clear itself after I fixed the issue when firmly inserting the pump harness into the DEM?

It might. When the code becomes inactive, VIDA shows it as yellow, not red.

The DEM-0007 appeared again today. After a few drives it went from Red to Yellow. Instead of clear the code I'll let it be to see if it clears itself.

[vtl]

Yellow will be there forever, until cleared.

[XC70Rider]

Yellow will be there forever, until cleared.

I suspected that but wasn't sure until you mentioned it. I always get the code CCM-DD12 regarding front drivers seat no heat. It never goes away unless I clear the codes then it re-appears after next start. It could be a blown fuse under the glove box but since I never use the seat heater I just let it be.

Appears the pump rebuild kit containing magnetic brushes won't get delivered until next week. I'll open up the DEM and check the connectors in a day or two

With DEM-0007 just randomly appearing and also turning Yellow it has to be a connectivity issue.

[XC70Rider]

A new connector can be found under the ref: Volvo, Seat 1J0 973 702 2-Pin
If you have the pin extractor it should be easy.

https://www.ebay.fr/itm/VAG-Volvo-Seat- ... 1438.l2649

Hi Antoine,

How did you find this oil pump connector? I ask because I want to replace the 8 pin connector that communicates the DEM to the REM.

Thanks,

John

[XC70Rider]

After filling it to the dripping point you have to suck out 100 ml or so, otherwise it will leak through the seal. Do you have a typical "oil ring" on the chassis around the flange? This is the oil thrown up through the seal.

No Haldex fluid leaked out via the damper nor final drive seal. I opened the fill plug yesterday and ~15ml dripped out of the over-filled Haldex. It was over-filled for 610 miles.

When I first replaced the broken temp/ pressure sensor I was still getting the DEM-0007 for nearly 2 weeks. As the miles went on it appeared less often. I also saw it active as red while I was getting a pressure reading from VIDA.

For the last 5 days of driving 200+ miles the code hasn't appeared. I can feel the AWD working and saw all 4 wheels spinning while in drive on jackstands yesterday. Do you think it takes time for the DEM to calibrate the new sensor? It's either that or the bad sensor connection has fixed itself.

If the code doesn't come back then I'll let it be. If it does strike back then I'll open up the DEM to fix the sensor connection, rebuild the oil pump, and search for a new 8 pin DEM connector.

[Antoine240bk]

A new connector can be found under the ref: Volvo, Seat 1J0 973 702 2-Pin
If you have the pin extractor it should be easy.

https://www.ebay.fr/itm/VAG-Volvo-Seat- ... 1438.l2649

Hi Antoine,

How did you find this oil pump connector? I ask because I want to replace the 8 pin connector that communicates the DEM to the REM.

Thanks,

John

Hi John,

I found the reference on the connector itself, luckily it appeared on the bay!
I also broke the tab on the old pump.

[XC70Rider]

A new connector can be found under the ref: Volvo, Seat 1J0 973 702 2-Pin
If you have the pin extractor it should be easy.

https://www.ebay.fr/itm/VAG-Volvo-Seat- ... 1438.l2649

Hi Antoine,

How did you find this oil pump connector? I ask because I want to replace the 8 pin connector that communicates the DEM to the REM.

Thanks,

John

Hi John,

I found the reference on the connector itself, luckily it appeared on the bay!
I also broke the tab on the old pump.

Hi Antoine,

Using a flashlight and magnifier I found the DEM connector PN 1394416

I ordered 2 of them at Digikey

https://www.digikey.com/products/en?key ... 1%E2%80%8E

The pins aren't included so I ordered a dozen of them

https://www.digikey.com/product-detail/ ... ND/3454199

Thanks,

John

[Antoine240bk]

This is good! hope it will fix the problem. PN 1394416 is for the harness

I have found the connector ref here: 1J0 973 714 - 8 pins

https://www.automotive-connectors.com/1 ... re=english