I have a 2005 S60 2.5T AWD and it appears that the AWD system is not engaging the rear wheels. I recently switched over from my summer tires to winter tires and noticed excessive front wheel spin and torque steer on dry pavement and snowy conditions. I recently took the car into an icy parking lot to test whether the AWD was functioning but the rear wheels refused to engage (nothing but front tire spin and the TC light going into a seizure on the dash). I've been doing some research on this forum and others and came across the following posting which discusses DEM failures on the Haldex. The link to the posting is below which includes the Volvo TNN:

http://forums.swedespeed.com/zerothread?id=90369

I'm hoping this is the culprit as it sounds like a relatively inexpensive and simple fix, however I was wondering if anyone else has had the same issues and whether this was the problem? I've heard the Haldex usually isn't the issue itself, which I am hoping is the case as I'm sure it isn't cheap. Any thoughts?

 

Just to clarify, I put the car on ramps to check out the DEM on the Haldex and it appears to still be attached with the boot in good conditioin (no cracks or holes). Can these still fail without actually becoming detached? Also, no DTC codes are appearing on the dash, however reading the link above, no code should appear on the dash for a DEM failure.

 

check the angle gear - any fluid oozing out?

 

I put the car back on the ramps and checked the angle gear and I couldn't see any leaks of fluids oozing out of the angle gear.

When I drive the car, it drives as it normally should with the exception to the AWD not engaging. There are no weird sounds/vibrations/etc.

 

Could certainly be the DEM but I worry about the angle gear.

Are you first or second owner?

 

I'm the second owner. I bought the car about 2 years ago with about 40,000 km's on it. There are approximately 75,000 km's on it now. Would the angle gear go that quickly? The car is heading to the dealership on Thursday, so I'm really hoping it's just the DEM and not the angle gear. Any idea what the angle gear is worth?

 

angle gear isnt a wear part but does fail from time to time (RARELY in a 2.5t)

 

Just as an update, I took the car to the dealership and it turned out to be the DEM unit that had an internal short in it. $2479 later, the AWD was working again, however two weeks after getting the car back, the same thing is happening. Could the DEM unit fail again that quickly? This car is going to cause me to go broke....

 

could be, sort of doubtful though.

that said it should have a 6 month warranty

 

Got the car back yesterday and the dealership said that there was a DTC code in the system that they have never seen before. The code was DEM E003, which after doing some research on the internet is a configuration fault error in the DEM. After they cleared the code in the system the AWD began to work again. They wouldn't admit this, but a configuration fault seems to me like something went wrong in the install of the new DEM unit. They are claiming that they have never seen this code before and that if it happens again that it could be an internal short in the AWD pump. Anyone know whether they are feeding me a line of s***? Anyway, right now the AWD is working again and there was no charge for the shop visit.

 

I just created a thread about the exact same problem. I tried using the search function before I posted but I must not have typed in the right search criteria.

Anyway, of the $2500 you spent to get your car working again how much of it was for parts?

 

The AWD stopped working about a week after having the computer reset again. I took the car back to the dealership and the replaced the AOC pump which also had an internal short. which blew the fuse on the AWD system and likely caused the DEM to fail earlier. Another $756 CDN later, the AWD is working again and there really isn't anything left to replace on the AWD system.

Camden, to respond to your posting, the total cost is now at $3213 CDN. Parts alone were $2056 for the DEM computer unit, $98 for the DEM software, and $398 for the AOC pump. Hopefully you don't have to replace both units.

 

The car is heading to the dealership on Thursday, so I'm really hoping it's just the DEM and not the angle gear. Any idea what the angle gear is worth?

 

Since I didn't need to replace the angle gear, I'm not sure what it's worth. I would guess around $2000. I only had to replace the AOC Pump and DEM unit.

 

I have this same problem with my '03 S-60. I took it to my mechanic who told me my DEM was dead and needed to be replaced in order to continue the diagnostics... The bill for that would be $2,700.

I just ordered the entire differential unit (DEM, AOC etc.) from Erie VoVo in NY for $425 + shipping. I should now have everything I need to get my AWD working. Also, others had mentioned the need to have the DEM programed by the dealer, Erie is pulling the unit from an '03 S-60 so I (shouldn't) need to have the DEM reprogrammed at the dealer.

I definitely saved a lot of money going used, and they have a part replacement warranty, too.

I'm excited to see how my AWD will drive, with working AWD, LOL.

 

I wouldn't get too excited yet. The DEM is programmed to the car. It doesn't matter if it is the same year or not, a used unit shouldn't work. I haven't personally replaced a DEM with a used one or tried to reporgram a used one, but on another site I answer Volvo questions on for pay, I have had two customers try a used DEM with no luck.

Please update this when you get the used one in, I'm curious how this works out.

 

Thank you ES6T for urging caution on this repair. I received the entire carrier unit from Erie VoVo and took it to my local mechanic yesterday. From what I read on the different forums here and other places I decided to have them switch out the entire differential and not just switch the DEM out. It cost more, but I saw that some people also have an issue with their AOC too, so I felt since I had the entire unit, I should switch it all out.

Since the part was taken out of an '03 S-60 there was no need to have the DEM programed by a dealer and it appears to be working just fine according to the mechanic.

As ES6T suggests, we should be cautious when buying used parts, but in this case, making sure the the part came from the same model and year seems to have done the trick.

Repair costs $470 for the Differential unit including shipping and $680 to install which included new axel seals and a few other gaskets, etc.

 

Interesting.

One thing to note, programming isn't just a matter of model year. While it may be working, I can almost guarantee there are codes stored in the CEM for not recognizing the DEM. Not likely to cause a problem, but keep it in mind if you ever have some strange network problem you need a dealer for. Let them know the DEM is used so they don't spend too much time looking in the wrong direction because of a code like that.