BCM-0095 & DEM-000B 2006 Volvo XC70 Topic is solved

Rvolvos · Post by **Rvolvos** » 19 Apr 2023, 22:16

Just replaced the rear differential included the AOC clutch with a low mileage one from a 2007 XC70. Because mine was pushing out fluid and making a growling sound while driving. See my other thread.
Replaced the fluids, filter, breather element and the temp pressure sensor with a new Volvo one. Reused my DEM, it was working with the occasional error Dem-000b, hence the new sensor. Tested the pump with 12Volt.

Running the car on jack stands all 4 wheel are turning.
First test drive; 200 yards anti skid message popped up. I had the laptop with Vida hooked up and saw , no oil pressure, no pump pressure, no pump current.
I swapped in another DEM unit and went for a second drive. Drove off our driveway backwards and sharp turning, felt like I hit something but was not. It was coming from the drive line.
If I step on the gas I can see the dem pump pressure going up. Did 2 pulls in gravel with and without dtc on and all wheel drive is working and immediately the anti skid message pops up. And no Dem pump pressure. After erasing the faulty codes it works again but as soon as you test the awd it shuts down.

BCM-0095 & DEM-000B are the codes the reappear after the anti skid error message. The fault codes have a faulty Dem in common. Anyone have experienced the same?

Attached 2 pictures of the Vida scan and information.

SmokingWIll · Post by **SmokingWIll** » 22 Apr 2023, 18:14

Hey man i have the EXACT same issue. Still trying to narrow down the source of the problem

Now. First off. your CEM1A64 code is likely due to the DEM not being the correct one for the car. That can be fixed by putting in the orignal DEM.

DEM-000B and BCM-0095 should be the only other 2 codes at that point

in trying fix the 2 above codes we have replaced the differential and haldex unit
Sent out the DEM to XEMODEX
Changed temperature/pressures sensor
inspected wiring
had the CEM and the BCM tested and confirmed good.

I have a hypothesis here. Can you monitor the speed sensors (From the DEM) using the grahpg whilst driving and see if they drop?

Ours seem to drop on occasion as if the lost communication or are refreshing

SmokingWIll · Post by **SmokingWIll** » 22 Apr 2023, 18:17

we also changed the pump 2 times and flushed the system countless times

Rvolvos · Post by **Rvolvos** » 22 Apr 2023, 22:11

SmokingWIll wrote: ↑22 Apr 2023, 18:14 Hey man i have the EXACT same issue. Still trying to narrow down the source of the problem

Now. First off. your CEM1A64 code is likely due to the DEM not being the correct one for the car. That can be fixed by putting in the orignal DEM.

DEM-000B and BCM-0095 should be the only other 2 codes at that point

in trying fix the 2 above codes we have replaced the differential and haldex unit
Sent out the DEM to XEMODEX
Changed temperature/pressures sensor
inspected wiring
had the CEM and the BCM tested and confirmed good.

I have a hypothesis here. Can you monitor the speed sensors (From the DEM) using the grahpg whilst driving and see if they drop?

Ours seem to drop on occasion as if the lost communication or are refreshing

Thanks much for the response, I will try to data log the speed sensors and report back.

Had the car aligned, it was way off even the front, which was not touched. But the anti skid message reappear after 20 minutes of driving. So I can rule that out. Checked the fluid level which was okay.

The vin of replacement rear diff is slightly newer than mine but should work.

I also reached out to Xemodex and they agreed that it is most likely the Dem by process of elimination. Now I not so sure.

SmokingWIll · Post by **SmokingWIll** » 23 Apr 2023, 16:16

See the PM i sent ya, well talk and get this fixed =) 2 brains are better than one

Rvolvos · Post by **Rvolvos** » 28 May 2023, 12:14

Installed the repaired DEM back into the rear differential. The AWD is working when accelerating from gravel without errors. Tried this 3 times with and without DSTC.
But when I make a sharp turn /full lock, steering wheel becomes heavy, then a big clunk from the rear and then the skid message pops up on the display. Same error messages and have to erase them 2x to disappear.
Tried this 3 times with the same outcome.

This never happened with the original rear differential. Thinking of putting back the original AOC clutch pack and test this.

Rvolvos · Post by **Rvolvos** » 01 Oct 2023, 13:03

Happy to report, the AWD is working for 3 weeks without Errors.

I have put back my original AOC clutch pack and a new pump. I tried to remove the pump from the newer purchased rear diff, but it was completely seized and had to reuse my old AOC clutch with housing.

Had the DEM repaired by Module Masters https://modulemaster.com/products/diffe ... vo~md_xc70. It had the typical communication issues.

Latest software for the DEM installed by https://www.datatransferring.com. Thanks @yagger.

Initially it did get the same problems, binding locking up when steering sharp, but I was able to drive longer and longer before the error occurred, until it worked without errors.
Apparently there is driving time needed to adapt. Have not heard of this before.

Post by **jonesg** » 01 Oct 2023, 16:22

modulemaster is reasonable price.
I might try them for mine.