Variable Induction System: Description and Operation

Intake Manifold Runner Control:

DESCRIPTION
The air induction system improves engine performance by using the Intake Manifold Runner Control (IMRC) assemblies. The intake manifold has two runners per cylinder, feeding each of the intake ports in the cylinder heads.

OPERATION
The IMRC is integral to the lower intake manifold. The assemblies are located between the upper intake manifold and cylinder heads, providing two air passages for each cylinder. One air passage is always open and the other passage switches from closed to open by means of a valve plate. The valve plates are opened and closed by the IMRC motor and valve assembly, which is controlled by the IMRC solenoid and powertrain control module.