Intake Manifold Tuning Valve - 3.0L (VIN S), 4.6L (VIN W) & 5.4L (VIN A)
Intake Manifold Tuning (IMT) valve is an electric actuator mounted directly to intake manifold. IMT valve operates a shutter device attached to electric actuator shaft. When electric actuator is energized it rotates shaft and opens shutter, allowing both sides of the manifold airflow to blend together. See Fig 1.
There is no monitor feedback to PCM from IMT valve to indicate shutter position (open or closed). PCM uses a positive change in Throttle Position (TP) sensor along with the increase in engine RPM from Crankshaft Position (CKP) sensor to open shutter.
When engine speed is below 2600 RPM, electric actuator will not be energized, allowing IMT valve shutter to remain in closed position (no airflow blend occurs). When engine speed is 2600 RPM or more, electric actuator is initially energized at a 100 percent duty cycle, causing shutter to open position (airflow blend occurs). Duty cycle then falls to about 50 percent duty cycle to continue to hold shutter open.