Valve Lifter Oil Solenoid Valve
The Dynamic Fuel Management cylinder deactivation system uses 8 valve lifter oil solenoid valves (one for each cylinder). The valve lifter oil solenoid valves are mounted in the engine block valley under the engine block valley cover. Each solenoid controls engine oil pressure to the intake and exhaust valve lifters on the cylinders selected to deactivate. Engine oil pressure is routed to the lifter oil gallery from an internal oil passage on the rear of the cylinder block.
The lifter oil solenoid valves are connected to a high control driver internal to the engine control module (ECM). The ground or control circuit for each solenoid is connected to a low side driver internal to the engine control module (ECM).
When all enabling conditions are met for cylinder deactivation, the ECM will actuate the high and low control of each solenoid control circuit in firing order sequence, allowing current to flow through the solenoid windings. With the coil windings energized, the solenoid valve opens, redirecting engine oil pressure through the valve lifter oil solenoid valves into vertical passages in the engine block lifter valley. The vertical passages, 2 per cylinder, are connected to the valve lifter bores of the cylinders to be deactivated. When vehicle-operating conditions require a return to V8 mode, the ECM will turn OFF the control circuits for the solenoids, allowing the solenoid valves to close. With the solenoid valves closed, engine oil pressure in the control ports is exhausted through the body of the solenoids into the engine block lifter valley. The oil passages of the valve lifter oil solenoid valves incorporate several bleeds in the oil passages to purge any air trapped in the engine block.