Trying to figure out the dreaded anti skid service required warning for my 2006 xc90 4.4. I initially replaced the SAS with no change. Today I replaced the YAW sensor under the seat unplugged the battery and let the ecu reset and upon startup it now show anti skid temporarily off. These seem to be the common issues with the warning. When I ran diagnostics in VIDA it did have a sas related code in the history. Where should I start looking now? Maybe something in the ABS?

The main symptom when the anit skid service required warning comes on is loss of AWD....as soon as the warning comes on it becomes FWD (found this out in the snow).

 

You have VIDA, You have a code. If you click on the code - VIDA gives you possibilities and things to check to be able to diagnose the problem. Have you gone over what VIDA thinks could be causing the problem? Or if there is not a code stored, you can go to "diagnostic trouble codes and associated procedures" and look up your previous codes - to see what VIDA thinks might be causing them.

This eliminates a whole lot of "got a code let's replace the part! DAMN IT, that didn't work - what should I replace next? I've got unlimited funds to throw parts at this so let's go!"

What exact VIDA code/s do you have?

 

Here is a list of the current codes....I unplugged the battery when I switched out the yaw sensor and it cleared the codes...I drove it for 60-70 miles to let it go through its drive cycles and relog the codes.

 

The BCM (brake control module) is not listed in your printout. Here's what Dice will talk to in my 2015 - I don't have SUM (electric shocks), PHM phone, TVM Tv module (and the other grey ones) so they all all grey. What does your module diagram look like? And note BCM is in my printed list. Is your VIDA talking to your BCM? - you should be able to click on the BCM icon and view parameters, activate, advanced -

 

The printout was from the fault trace tab. I went to the network tab and ECM, BCM, and DEM are red and their tabs say not responding. In fault trace ECM, BCM, and DEM are grey. CEM is red.

 

"In fault trace ECM, BCM, and DEM are grey" -

A few years ago I had a problem with a clone DICE I purchased - it would not talk to some modules. (in several cars I tried) The vendor sent me a replacement that talked to all of them. You might have bus problems - here's that page from the wiring book - note the brake and diff modules are on the same can bus wires/connectors into the CEM. Water damage is also common with your CEM and note the xemodex failure symptom at the bottom of the page "wont communicate with BCM"

 

Well I guess I'll start by checking the CEM...I'll try and check the connections for corrosion and check the #15 fuse for power.

 

Not easy to get to -

 

Not to bad to get to....2 t25 torx. I pulled all the fuses and checked them....all fuses are good. I also probed all the fuses for voltage....got no voltage readings on any of the fuses Key on engine off and key on engine running. I didn't go further than that until I read a bit more into the wiring. I used both a multimeter and a cheap fuse puller/tester and nothing.

 

If your high beams work you will have power at fuses 22 and 23 (when they are turned on) on the CEM. If not your test is not valid.

 

I retested (I was using a bad ground point) All fuses have voltage except #35... I can't find what it's suppose to do?

 

I'm still trying to diagnose the anti skid, I'll mess with vida some more this coming week and give you an update...in the meantime I took a break from that and replaced the dryer/condenser, expansion valve, air conditioning compressor, and o rings...vacuumed the system for an hour....added 36 oz of R134a and checked ac gauge readings...40 degrees out the vent and 40 psi low and 210 high....and the fan kicks on immediately...fixing my prior problematic and warm ac.

Notes on the AC work: It's very straight forward with no major complications. The worst part is the fan shroud bolts on the top of the radiator...they are tucked under the radiator support making it almost impossible to get with a wrench or ratchet...you'll need a good combo of swivel extensions and wobbles to get them both in and out. Also, the bottom bolt on the compressor...you'll have to use a 10mm wrench, if you use a ratcheting wrench that isn't reversible don't go to far (ask me how I know), it will get stuck between the subframe and compressor...and lastly the allen bolts on the expansion valve are very tiny...i didn't strip mine by you very easily could...make sure your allen wrench is fully seated in the hole.

 

Update: I think it's fixed. I've been driving the fix for the last week and have had no anti skid warning come on. It ended up being either the pump or filter (replaced both) on the haldex unit. The fluid looked new but the filter looked dark. I had a local volvo shop scan and clear the codes. They were unable to diagnose it as the scan tool wasn't communicating with all the modules (I had the same issue with my VIDA laptop). When they cleared the codes I took it home and plugged in my vida and was able to communicate with all the modules...previously the BCM and DEM were coming up red and saying unable to communicate. When I was finally able to check the DEM and BCM for codes I got a haldex pump pressure high code...which led me to order the pump, filter kit, and fluid. I did the rear differential fluid as well since I was down there.