Please help refine my plan to DIAGNOSE my XC70 AWD problems

[celebrity208]

I plan to diagnose my AOC soon. Here is my plan since I already know that my angle gear and trans coupler are good:

1. Check AOC DEM fuse (#16 I think)
2. check resistance of the AOC oil pump by using multi-meter on the pumps leads
   (I think I'm looking for something between infinity and zero).
3. check oil level in AOC
   
4. check operation of pump by applying 12v to the leads to see if the motor spins
5. check pump filter (remove pump and inspect the screen)

Does anyone know if there is a way to check/diagnose the pressure switch?

Finally, if it turns out that I have a bad pump, and I replace it, do I need to “reprogram” the DEM?

Thanks all!
Clayton

[JRL]

Yes, have it read in VIDA.
If it or the DEM is bad you will have a stored code(s) and the codes are different for a bad DEM module and/or just a bad pressure switch.
Hell of a lot quicker and easier than your plan!