[amidgeha]

Intake Manifold Runner Control Circuit Low

The Intake Manifold Runner Control (IMRC) is an electrically actuated system consisting of a motorized actuator with an attaching linkage for each housing on each bank. The linkage attaches to the housing butterfly plate levers. Each IMRC housing is an aluminum casting with two intake air passages for each cylinder. One passage is always open and the other is opened and closed with a butterfly valve plate. The housing uses a return spring to hold the plates closed. The motorized actuator houses internal switches to provide feedback to the Powertrain Control Module (PCM), indicating linkage and plate position. Under about 3000 rpm the vacuum solenoid will be energized. This will allow manifold vacuum to be applied and the butterfly valve plates to stay closed. Above approximately 3000 rpm , the vacuum solenoid will be de-energized. This will allow vacuum to vent from the actuator and the butterfly valve plates to open.

Cause:
Intake Manifold Runner Control (IMRC) monitor signal shorted to power
Faulty Intake Manifold Runner Control (IMRC) actuator
Faulty Intake Manifold Runner Control (IMRC) solenoid
Damage Powertrain Control Module (PCM)
Blocked vacuum hoses

Symptoms:
Check engine light