Electric Folding Rear Head Restraints (S60/S80)
There are solenoids on the rear head restraints if the car has electrically folding head restraints (not the center rear seat). The solenoids can fold the head restraints when reversing, for example. The solenoids are powered by the rear electronic module (REM).
The head restraints are folded using a switch on the lower section of the climate control module (CCM). The head restraints fold down when the switch is pressed. The head restraints fold back up manually.
There are diagnostics for the switch via the climate control module (CCM).