Intake Manifold Tuning Valve Diagnosis

INTAKE MANIFOLD TUNING VALVE DIAGNOSIS

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

TEST DESCRIPTION

Steps 1-2:

Steps 3-4:

Steps 5-6:

Steps 7-9:

Steps 10-13:

The number below refer to the step number on the diagnostic table.
3. This step determines that the IMTV and linkage is moving correctly and not loose or damaged.
7. This step test for a faulty IMTV solenoid. If the IMTV solenoid is commanded On, there should be vacuum at the vacuum actuator. If the IMTV solenoid is commanded OFF, there should be no vacuum at the vacuum actuator.