Low oil pressure
Restricted oil passage
Engine mechanical condition
Faulty Multiple Displacement System (MDS) Solenoid
Multiple Displacement System (MDS) Solenoid harness is open or shorted
Multiple Displacement System (MDS) Solenoid circuit poor electrical connection
Engine Light ON (or Service Engine Soon Warning Light)
When all the criteria has been met,power is supplied to each Multi-Displacement System (MDS) Solenoid when engine is making a transition from 8 cylinder mode to 4 cylinder mode. By actuating the solenoid, oil pressure is raised to the pair of lifter that coincide with each particular solenoid. The oil pressure pushes in the locking pins that allows the lifter to collapse, decoupling the valves and camshafts.