Circuit/System Description

The intake manifold runner control valve functions as a port deactivation (PDA) valve by controlling the flow of air to one of the intake valves in each cylinder. The runner control valve consists of an electric motor, a valve linkage and four butterfly valves. The motor moves the linkage, which opens and closes the butterfly valves in the intake manifold. In high flow conditions, the valves are open, allowing maximum air flow through both intake valves. In lower flow conditions the valves close, blocking air flow to one of the intake valves, forcing the majority of the air to go through the open runners to feed the other intake valve. This in turn causes the air to form a swirling motion as it enters the cylinders, contributing to a more complete mixture of air and fuel. This improves combustion in relatively low flow situations. The primary reason to use the PDA is to improve fuel economy by increasing combustion stability and dilution tolerance.

Ignition voltage is supplied directly to the intake manifold runner control valve motor. The engine control module (ECM) provides a low side drive control circuit, a position feedback circuit and a ground circuit. The ECM controls the motor by pulse width modulating (PWM) the control circuit to ground. The feedback circuit provides a signal to the ECM relative to the position of the butterfly valves. The ECM can determine if the control circuit is open, shorted to ground or shorted to a voltage by monitoring the voltage on the position feedback circuit.