2006 xc70 awd rear end delay

[j4nx]

Hey,
I bought 2006 xc70 2.4 D5.
When snow and ice came, i noticed i have no awd. Checked fault codes with vida and it said that pressure pump is faulty.
I went to rockauto website and bought DORMAN aoc pressure pump for pretty cheap money (under 150$). Installed it with new oil and filter and went to test drive. I had like 3 second delay and spinning on front wheels before rear end kicked in roughly. Then checked codes with vida again and there was code that was saying that Hydraulic pressure faulty value. i ordered used pressure/temperature sensor and installed it. Then went to test drive and rear end kicked in instantly. Then on my way home (50km) i wanted to try again and went on icy area. Tried it and ...about 2 seconds before rear end kicked in. Seems like when rear end gets warm or something then the delay is back because on another morning i went to test again and had rear end kicking in instantly again. when i drove around for 10-15 mins and tried awd ..again delay is back.
Could it be the used temp/pressure sensor or something else? since it is better than before with my old sensor.
I havent checked the codes with warm engine now. I'll do that asap.

thanks

[oragex]

Not sure I'd use these brands for these specific parts. Better source a used Volvo one that was recently replaced (the two year digits should be stamped somewhere on it in a small circle)

The awd was rather problematic for your year, angle gear, controller (DEM), pump etc. On top of the answers here I'd also suggest search the forums, there is a lot of information on this.