AWD not working, what in the Haldex is wrong?

[dagibby]

bevel gear and splined coupler are fine, shaft turning to rear diff. What could keep the Haldex from engaging? Something about a parking brake sensor? I have checked the sensor in the AOC that gets pluged up, it's clean. Oh yeah, 2003 47k

[phlight24]

I've been battling the same problem for a while now. I had a dealer tell me to change the entire rear differential. I didn't buy into that, and took it to a local shop who specializes in Volvo's and other european cars. After a few hours of troubleshooting they determined that the module that controls the rear diff. (primarily the pump) was not working. In the process of troubleshooting they were able to get it to work by flexing and prying on the module. Something is definately broke. Getting a new module installed on Fri. Cost about 1800 dollars. 1500 for the part. Has to be done in the shop. Module needs to be programmed when installed. Good luck.

[dagibby]

Vadis indicated a faulty pump in the Haldex. $220 for the part, $60 for the Vadis diag. $30 for Haldex oil. Replaced it myself, AWD works great. Replacing the pump is a pain as you have to remove the drive shaft.

[skibo]

How many wires go to the Haldex? I am intrigued by that thing.

[n00bkiller944]

How are you sure your AWD isn't kicking in? Is it throwing codes?