[SwedishBus]

The electric seat on the V70 and similar with the memory function is fairly easy to diagnose when it fails. The faults that are likely to occur fall into two broad catagories;
1) Faults with the motor/s and associated harnesses
2) Faults with the switch panel and associated harness

There is, of course, the possibilty that a fault could have occurred in the control module under the seat, however this is much more unlikely than a straightforward electro-mechanical fault elsewhere on the seat, so unless all other avenues have been explored, it's not worth swapping-out the module. Likewise, if the power to the seat has failed at the fusebox, etc., then that will need dealing-with first.

To narrow the two categories down, a few tests of the switch panel are required;

a) Does the seat move with any switch input at all? If not, then check the fusebox and the supply +12v and ground to the seat module first, before stripping the switch panel out for further tests

b) Does the seat not move on one or more switch inputs, but otherwise moves if the Memory buttons 1, 2, 3 are pressed? Again, the seat switch panel needs stripping out and repairing.

c) Does the seat not move on some switch inputs, but a clicking can be heard from under the seat on those failed movements? This is more likely to be the motor/s within the seat, requiring the seat itself to be stripped down. If the backrest angle function is the failed movement, this can be done with the seat in-situ in the car, otherwise it is going to be easier to remove the seat completely in order to repair it, as the raise/lower and forwards/backwards motors are all underneath the seat cushion - very tight to access for motor removal.