Intake Manifold Tuning Valve Diagnosis

Intake Manifold Tuning Valve Diagnosis

Circuit Description

An intake manifold tuning (IMT) valve or variable geometry induction system (VGIS) is used to change the intake manifold plenum configuration. When the IMT valve is open, the intake manifold is configured to one large plenum. When the IMT valve is closed, the intake manifold is configured to two smaller plenums. The IMT valve improves engine performance at low and high engine speeds depending on the engine load. Ignition 1 voltage is supplied directly to the IMT valve solenoid. The engine control module (ECM) controls the solenoid by grounding the control circuit. The IMT valve system contains the following components:

* The IMT valve solenoid
* The IMT valve vacuum reservoir
* The IMT valve vacuum actuator
* The intake manifold tuning valve
* The intake manifold

Test Description

The number below refer to the step number on the diagnostic table.
3. This step determines that the IMT valve and linkage is moving correctly and not loose or damaged.

7. This step test for a faulty IMT valve solenoid. If the IMT valve solenoid is commanded ON, there should be vacuum at the vacuum actuator. If the IMT valve solenoid is commanded OFF, there should be no vacuum at the vacuum actuator.