53 replies to this topic

[NJGreenBudd]

So it turns out that mine is a First Gen Haldex controller compared to the later Gen 3s. Look here: http://www.awdwiki.com/en/volvo/ , the 2002 S60 apparently comes with the First Gen Haldex system... http://www.awdwiki.com/en/haldex/ for more info about the generations...

I'm curious if my e-brake could be playing a part here, it doesn't work right now and might be conflicting with the DEM???

[NJGreenBudd]

Just spoke to Chris @ XemodeX and he really helped clear things up. Yes indeed we are looking at 1st Gen Haldex unit here. Based on the fact that it is getting power and ground, has network integrity, shows white in VIDA but throws a code when disconnected we can assume it's a fault on some module inside the controller. Something about a hi and lo side of the CAN network and a specific part of the DEM processor that is common to the 1st Gen Haldex unit. He says they have not been able to repair this particular failure mode because of it's extremely small and complicated nature. Good news is that you can simply swap in a another used controller in this year with no need for software updates.

So I'm off to find another controller and give it a shot.

[NJGreenBudd]

Bought a low mileage complete rear carrier w/ DEM for $200 and swapped in the module. The clip was busted so I went ahead and joined it to the old connector and reinstalled. Still doesn't show live data in VIDA because 1st Gen Haldex don't do that. But when I tool it up the rainy, gravel driveway and boosted it didn't spin the front tires, no traction control lights, just pure AWD action.

Quote

AWD works just fine again. yay!

[NJGreenBudd]

Okay this sucks, recent development as of this mornings commute to work: AWD doesn't work again. Ugg. It just spins the front tires in the rain, lots of torque steer and very little forward movement. I am thinking the AOC pump might be shorting out and drawing more voltage and burning up the DEMs? When I tested the pump to verify it worked I noticed it was kinda loud, I did not test the current draw though.

Now I do have another AOC pump from the low mileage carrier sitting here. But I'm still going to be short a working DEM. I am thinking of opening the DEM and trying to see if it's visibly melted or burned up. I think Chris at Xemodex can repair the damage from the pump shorting anyways. When we spoke last he mentioned that there are certain failure modes we can fix and some which he can't. We were under the assumption the problem with my first DEM was in the communication network side of things because it wouldn't read in VIDA. After fixing the AWD by replacing the new DEM and seeing it still not read in VIDA we figured out the First Gen Haldex/DEM units do not show live data unlike the newer Gen 2 units. Since the new DEM failed after only a week we can assume it was due to the pump drawing too much current, in which case Christ should be able to repair both DEM units I have here.

So lesson learned, when doing the intial trouble shooting for 1st Gen Haldex, make sure to not only test the pump for activation but also check it for current draw. This might prevent your new DEM from failing immediately.

[lookforjoe]

Hope you get it sorted out - sounds like you've covered quite a learning curve with this generation.

[JRL]

I had one with partial, intermittent AWD.
It was a bad Haldex pessure sensor.
Less than $80 for the part

[NJGreenBudd]

Lookforjoe, thanks man, we'll get it sorted out eventually but this was a disappointing setback with winter being so close. Part of my difficulty is the lack of information that pertains to this generation Haldex controller, much more info out there about the newer versions.

JRL, was that a first gen Haldex controller or newer? I can't find any part #'s for pressure sensors for my year, when the DEM is taken off there are no sensors apparent unlike newer controllers where they are visible on the mating surface of the differential. I believe this year the sensors are integral to the controller.

I'll update as we go along but the basic plan of attack is to swap the AOC oil pump for the lower mileage unit and then replace the DEM again with either another used unit or a rebuilt unit.

Thanks and have a great day,
NJGB

[winnipegtibook]

Anyone know where I can find the Tech-Net Note (TNN) 40-02?

[NJGreenBudd]

I might be able to upload it tonight for you.

In related news, I have sourced another low mileage rear carrier complete with DEM, this one only has 45,000 miles and looks great, no damage, bolts are still shiny, etc.... I am going to actually swap the entire AOC section, split it from the final drive and save some time removing the whole assembly. I'm just waiting for the AOC gaskets to get here from Tasca and I'll post an update with pics of the swap.

[NJGreenBudd]

I'm sorry I don't think they have the tech notes in VIDA, unless I am missing them or not looking in the right place.

Here's the AOC swap:

Fixed the AWD again today. Hopefully for a longer period of time now that the entire AOC unit has been replaced.

Drop the exhaust:



Unhook the sway bar and push to side to release elevator bolt for rear carrier:


Remove driveshaft:


Make sure fluid fill plug is open / not stuck before draining assembly. loosen fill plug:


Remove AOC to final drive bolts:


Remove AOC assembly:


AOC and Donor Rear Carrier:


New OEM gasket on new AOC:

[D s50r]

Hey idk where you are but if you have any more issues or need additional help I'm a tech at a dealer and could help you out with tech net notes or get ahold of a Volvo engineer for you

[NJGreenBudd]

Hi, thanks for the offer, I'll certainly keep you in mind. Maybe winnipegtibook still needs the TNN40-02...

The car is driving great again, restored AWD makes a huge difference even in the dry but I could really go for some snow now.

[winnipegtibook]

hi,

the tnn 40-02 would be greatly appreciated. i am still working through my own awd failure.

[D s50r]

I'll look it up today

[winnipegtibook]

Thanks a bunch! I am starting my investigation of my non-functioning AWD. I don't want to hijack the thread, but curious to know if NJGreenBud (or others) can offer
advice on the following codes that were pulled a few weeks back.

- BCM-0094 (note - in the details, it says pump engine, status "not active". Does this mean the haldex pump is kaput?). I don't understand what this frozen value field means.
-BCM-0100, 0115
- ECM-510F, 928C, 9400

Note -there were DDM, PDM's as well, but this is related to windows and mirrors (that much I figured out).

From the BCM and ECM's, it seems that the starting points should be:
-check DEM sensor / connector
-AOC (connector, grounds, check the oil, clean up the sensor....maybe replace it with the oil while we have it opened?)
-check CAN cable

[D s50r]

Check fuse for dem in the rem then check for power at the dem connector then check for power at the pump connector if power at dem connector and no power at pump the dem is your problem

[winnipegtibook]

Looks like DEM is the problem. DUMB question - how on earth do you get the two connectors off the DEM? I can't remove the retaining clips and just can't figure it out (and feel like such a tool).

NJGreenBud or anyone else?

[D s50r]

90* picks and slide it under the one side and turn which will release the clip and pull on the connector

[winnipegtibook]

Thanks! This advice helped a little bit, but the connectors were incredibly brittle, and suffered some damage (see pics attached). I tested to see if they still "connect" and they do.

Perhaps a bit of electrical tape or a hose clamp?
 photo 1.JPG   84.88K   5 downloads  photo 2.JPG   75.57K   4 downloads  photo 3.JPG   70.9K   5 downloads  photo 4.JPG   88.18K   4 downloads
The unit wasn't super "dirty" on the backside, but from my chats with Xemodex (amazing tech help) the codes seemed to relate to a bad DEM. Now that winter's here, I need AWD again (especially on the Canadian prairies).

[D s50r]

I would stick some "dumb dumb" it's kind of like thick tar to hold the connector on