Skid assist, Parking Sensor, Fault Diag

[Hugomulligan]

Hi All,
I do hope this will help someone,
I have 07 XC90 D5 SE Sport
About 4 weeks ago i had a plethora of faults come up virtually all at once

Skid assist service required
Parking sensor service required
ABS service required

Thankfully a few months ago i got a VXdiag from sirobb, which was going to become invaluable,
First was the ABS, vida pointed to front drivers side ABS ring, easy peasy followed Simon Robbs youtube video and done in no time

so now comes the fun,
Skid assist can be lots of things, steering angle sensor, yaw sensor, haldex pump, DEM, so rather than just throw lots of money/parts/labour at it i thought lets really investigate this, So i trawled all the forums without any definitive answers,
I contacted Simon Robb who gave me a refresher course in how to use VXdiag/Vida, and suggested to follow the fault traces on vida and check connections, so back on vida, so Vida couldnt connect to DEM (differential electronic module) or PAM (park assist module), Simon messaged me with guide how to check DEM and also the Haldex pump, so under i crawled and and tested the connections at the DEM which is near rear diff on the haldex,
No 12v at the connection.
So now test the haldex pump using spare battery,
Pump is working, thats a relief.
Now this is pointing to the REM (rear electrical module) or in laymens terms the Fuse box in the boot at the left side where you access the light cluster.
Checked the fuses, all good.
So power into REM but no power coming out. so i put a call into Lukas at Volvodiagnostic in Tilbury. Really helpful company, as soon as i explained the issues Lukas asked if my parking sensors had stopped working too, as soon as i said they were showing a fault he said that this is quite common and it is usally a fault in the REM and if i sent mine to them they would repair and send back, (£90 + carr) So i sent it off and today got it back. Refiitted the REM and turned ignition on, fired up and NO FAULTS . job done.

Big thanks to
Simon Robb (VXdiag and for being a genuine nice guy)
Lukas at Volvodiag great company and great service

[KAMXC90]

Really good, explained whats up, how you checked and gave a solution.

I have messages up on a frequent basis that might be similar to yours, so will investigate.
I get;Parking sensor
Anti-skid
Soot Filter

pretty often.

As the centre consul has very few switch lights on at night I wondered if someone had removed for some reason and that may have also in turn affect the various sensors, you explanation say no, so maybe safe to see what some switches are always dark.

Ken