Variable Induction System: Description and Operation

Intake Manifold Runner Control (IMRC)
When engine speed is below 3,200 rpm, the IMRC Solenoid Valve 1 and IMRC Solenoid Valve 2 are activated by a signal from the PCM. Intake air flows through a long chamber path, increasing torque at low RPM.

When engine speed is 3,200 - 3,600 rpm, the IMRC Solenoid Valve is deactivated by the PCM. Intake air flows through a short chamber path, increasing mid-range torque.

When the engine rpm is above 3,800 rpm, the IMRC Solenoid Valve 1 and IMRC Solenoid Valve 2 are deactivated by the PCM. This creates a very short intake path and increases high-speed torque.