Variable Induction System: Testing and Inspection

Intake Manifold Runner Control System Diagnosis

Circuit Description

An intake manifold runner control (IMRC) valve is used to change the intake manifold plenum configuration. When the IMRC valve is open, the intake manifold is configured to one large plenum. When the IMRC valve is closed, the intake manifold is configured to two smaller plenums. The IMRC valve improves engine performance at low and high engine speeds.

Ignition voltage is supplied directly to the IMRC solenoid. The engine control module (ECM) controls the solenoid by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.

Diagnostic Aids

Inspect the IMRC solenoid valve for witness marks that indicate that the valve was hitting the intake manifold. This condition may be temperature related.

Test Description

Step 1 - Step 7:

The number below refer to the step number on the diagnostic table.
2. This diagnostic table will only diagnose the mechanical portion of the IMRC solenoid. If there is a DTC set for the IMRC solenoid, refer to the appropriate DTC table.