Could the non-functional AWD be an easy fix on a 2007 XC70?

[AylmerQc]

I'm selling our XC70 and most respondents to my ad ask if the WAD is functional, which it isn't.
I'm not sure what the issue is with it, I bought it that way 3 years ago and haven't driven the car much since but I get around in it ok.
A fellow came this week and suggested that the also non-functional ABS could be the problem with the AWD.
The front drive side toner ring needs replacing. The way things are, I need to remove the ABS fuse otherwise the car goes into limp mode. According to the fellow, that's likely the problem with the AWD...(?)

[abscate]

If the tone rings are really bad the car loses wheel speed information and lots of things get disabled.

[Blacklab467]

It could be the issue but it might not work even with the ABS tone ring replaced. There's lots of things that could go wrong with the AWD. I'd first jack the car up and check the propshaft and see if its mechanically connected to the angle gear ( ie: are the splines on the angle gear and collar sleeve good). Maybe the previous owner removed the propshaft already. Then, go further back and check the pump on the Haldex, these are prone to failure. A scan with Vida can also tell you if the DEM is working and the status of the AWD. It could also be a fuse in the back, not sure what that fuse number is.......sorry.
In short, It could be a quick fix but in my experience it's probably something expensive and difficult to change.

[erikv11]

What they said!

AWD on the P2 cars is a big can of worms and most 07 XC70 cars do not have functional AWD unless the owner has been fixing it. The car drives pretty well as FWD but some really want the AWD e.g. for safety reasons.

1. AWD will for sure be disabled by a bad tone ring, if you want to get to the bottom of the question then you must first repair that tone ring and replace the ABS fuse. Cheap but a pain to DIY, probably expensive at a shop.

2. However, usually the problem is the Haldex pump in the back. In order of most to least common:
> 2a. Bad pump. If it never been replaced then it's broken. They usually last about 7 years or 100k, less if aftermarket. They can last longer if the pump oil and filter are changed regularly but most people do not do that service.
> 2b. Haldex fuse randomly blown (fuse 23 in the rear cargo compartment, 7.5 A, for the DEM). Cheap and easy fix if it's the root problem!
> 2c. Bad pressure sensor at the DEM.
> 2d. Bad DEM itself.
These problems are pretty easy to diagnose with VIDA and moderately-to-very expensive to fix. Also see https://xemodex.com/blog/category/blog/ and https://xemodex.com/us/diagnostic-flow-charts/.

2. In second place for frequency but still common enough that I've seen it on one of three cars that I own, the angle gear collar may be stripped. This is easy to diagnose by getting all four wheels in the air and very expensive to fix.