no drive to rear wheels!

[GJB]

Now have answer it was the pump motor on rear wheel drive haldex unit had failed replaced with new oil and filter.

[Doityourselfer]

Also no AWD. 2005 XC70. Took it to shop and pulled code DEM-0006 and CEM Communication fault with AOC. Put car on lift, reset code and pump came on and all 4 tires turned when put into drive. Drove home, and again, no AWD. Bad pump?

Thanks, Steve

[Clan]

Originally Posted by Doityourselfer

Also no AWD. 2005 XC70. Took it to shop and pulled code DEM-0006 and CEM Communication fault with AOC. Put car on lift, reset code and pump came on and all 4 tires turned when put into drive. Drove home, and again, no AWD. Bad pump?

Thanks, Steve

if the CEM cant communicate with the AOC then it cant check out the pump . If teh DEM has 12v and earth and the two network wires are ok it has to be a faulty DEM . DEM006 does point to a faulty pump , but if you apply 12 volts and earth to the two pump wires in it's plug does it work?

[Doityourselfer]

What's strange is that when they reset the computer, the AWD worked. I heard the pump come on. Then drove 100 miles, and no AWD. I'll check on 12 VDC this weekend and see what I find out.

Steve

[Doityourselfer]

One more quick thing to add. My transmission went out and I found a good used transmission that I had put in. That's when I noticed that the AWD had quit. Took it back to the transmission place, and they checked and the driveshaft to the rear dif was working, but the clutch wasn't engaging. Then took it to Volvo shop and reset computer. Worked then, but not now. I live in the Rocky Mountains and going anywhere can be a challenge.

[Gazdok]

Originally Posted by Clan

This is normal , what makes you think you have a problem on the road ? Only on 2007 and later models with " Instant Traction" do all 4 rotate from standstill ...

I have a 2006 PII V70 AWD. I had an antiskid message and read errors and then put it on a ramp.

All 4 wheels do rotate from stand still. The rear ones at a slower rate than the front ones though.

Originally Posted by Doityourselfer

One more quick thing to add. My transmission went out and I found a good used transmission that I had put in. That's when I noticed that the AWD had quit. Took it back to the transmission place, and they checked and the driveshaft to the rear dif was working, but the clutch wasn't engaging. Then took it to Volvo shop and reset computer. Worked then, but not now. I live in the Rocky Mountains and going anywhere can be a challenge.

Look for a second hand unit (AOC) or second hand pump if any breakers sell them separate.

[barbershores]

I had my awd shut down on my 2004 v70xc. Rear wheels did not work. Sometimes would, then would not. Found that I had other odd problems too. Solution was actually to replace the ignition tumbler and switch. Tumbler was one problem maybe, switch was another. What was found was that when the rear wheels did not turn, if I pushed in the key straight towards the center of the steering column, they would start turning. Other intermittent electrical problems associated with this.

Later, the rear wheels would stop when I got an ABS error. When this error occurs, my tripometers would "------" out, and the odometer reading would freeze and not increase as I drove. No ABS would work. It was fixed when I replaced the abs module located beneath the brake master cyclinder. Local dealer wanted $1,360 to do the job. They would have had to order a new module from Sweden pre programmed with the vin in it. Instead, I purchased a rebuilt unit from xemodex.com for $499 including shipping and returning core. Probably took me 2 ours to do. Someone that knew what they were doing can probably do it in 30-40 minutes.

Used this video to figure out how to replace. Takes a special E5 torx socket. This is a female socket, not the male.

http://www.youtube.com/watch?v=wtyg6o7QTXE

Not sure if this is your problem. The abs error light coupled with the tripometer odometer errors indicates that the module has frozen and isn't communicating. It is often intermittent.

Best of luck,

Barbershores

[snakedog]

Hi, I have no drive to the rear wheels. The prop is connected and turns as it should (late 2006 model)
The fuses are both ok and have power with the ignition on and I have power and earth at the DEM. If I power the pump directly using the pump multi-plug the pump runs fine.
I cant feel the pump prime when the ignition is first turned on or when the engine is run, would a faulty pressure switch cause this? I'm not sure what the common fault is with the pressure switch, if it's telling the DEM the pressure is ok, it would make sense that the pump wouldn't run.

My dilemma is : could this be the pressure switch inside the DEM, seen lots of talk about the pressure switch. Unfortunately I'm off the coast of Scotland and don't have access to a Volvo dealer and don't want to have parts shipped in if I don't need them.

[snakedog]

Replaced the oil pressure switch and stripped and cleaned the DEM. works perfectly now, happy days