Experiencing slow electronic death 2003xc90

[cjhof]

Bought used 2003 xc90 2.5T, dealer sold as-is, and ran great as I expected. Long story short, the ICM went out 2 weeks after purchase. 3-4 months later windshield wipers, front and back, turn on sporadically (sometimes never turn off during trip). Couple months after that the CCM stopped working. Shortly after that the dash gauges would work most of the time, now they come on for few seconds every 10-15 start up vehicle. Control lights on steering wheel and most of radio/phone dials light up. I had 3 messages (Reverse warning service, Anti-skid service, SRS-airbag service). Turn signals and lights still work and seat belt light in rear view mirror stays on constantly. Any pointers of where to look would be greatly appreciated since dealership wanted a 3-5 hour diagnostic at $125/hour just to tell me what's wrong.

[doublebug]

ICM can be replaced by used one from 2003-2004 MY Car.
Front windshield wipers are controlled by CEM. Rear one is controlled by REM but usually it itself is bad.
"CCM stopped working" can be worn temperature sensor inside it.
as for dash gauges that is known issue with these MY. Can be replaced by from 2004 MY. It is more reliable.
SRS issue can be because of bad DIM (dash gauges)
Anti-skid because of turn wheel sensor or issues with DEM (haldex) if it is present.
Any way at least reading with DiCE and VIDA is necessary to get more information.
Try to ask dealer for the reading and get the list with codes.

[Masscomguru]

have the battery tested first. Low voltage from the batter can play games with the on board systems.

[oragex]

As above, not the battery, but the alternator checked first - it's pulley (along with the a/c compressor pulley) tend to wear past 120k miles. Also check the alternator regulator. An alternator that doesn't charge properly will cause a lot of weird issue on this car. If the battery is weak, check first the alternator because it's the alternator that is charging the battery. Lastly, inspect the thick electric cables from the alternator, and near the battery for cracks, corrosion (battery terminals)

Be aware that the dash gauges (DIM) go bad on the 2003 and the unit needs repaired, check out repair services on Ebay

[ALF1]

If you have a sunroof, the XC90 sunroof drains are notorious for becoming plugged with debris, backing up and overflowing down into the foot wells. You'll notice a sloshing sound and wet carpet. Lots of wiring goes on under the carpet...especially passenger side which can lead to:
Yaw sensor floor and failure....just dry it out.
Radio failure
Etc.
Look for Sunroof Drain topics.
Look for Yaw Sensor fix topics.
etc.