Variable Induction Control Valve: Description and Operation

Electronic Engine Controls















Intake Manifold Tuning (IMT) Valve
There are two intake manifold tuning (IMT) valves, an upper and a lower, sometimes referred to as number one and two respectively. They are a two position (open and close) device used to create a variable air intake system. The IMT valve positions are switched by signals from the ECM to optimize torque across the engine's speed and load range. The upper IMT valve opens between 4,100 and 6,150 rpm while the lower IMT valve opens between 3,900 and 6,150 rpm.