The low to mid-range torque of the engine is enhanced by the Intake Valve Timing (IVT) control system, while at higher speeds it makes more horsepower. The PCM-controlled intake Valve Timing (IVT) control solenoid valves either delay or advance the opening and closing instant of intake valves by changing the path and pressure of oil flowed through the intake cam-shafts. The PCM processes information sensor inputs like crankshaft position, camshaft position, engine speed, and engine coolant temperature to respond with ON/OFF pulse duty signals to the intake valve timing control solenoid valves which are used to determine the ideal intake valve angle. These pulse duty signals are then manipulated by IVT control solenoid valves in order to either change the quantity of oil or its direction of flow through the camshafts or make it stop passing through them. A longer pulse width signal issued by a PCM advances a valve angle while a shorter pulse width retards a valve angle. When ON and OFF pulse widths are equal, oil pressure flow ceases in IVT solenoid valves resulting into immobile intake valve angle. On 2003-2006 models, these IVT control solenoid valves are mounted on top of the rear timing chain cover. On 2007 and 2008 models however, they form part and parcel of valve timing control covers that are small access covers on front portion of timing chain cover. Top portion of Timing Chain Cover houses Intake Valve Timing Control Solenoid Valves. If there is an engine harness routed over the top of the IVT control solenoid valve remove it from its clips so that you have enough room to remove this solenoid valve completely from there. Remove electrical connector from IVT Control Solenoid Valve. Take out bolts that attach transfer case shift motor assembly to adapter housing and separate transfer case shift motor assembly from adapter housing leaving old gasket in place. Remove the gasket from the IVT control solenoid valve and discard it. It is the best to use a NEW gasket during the installation of either the old IVT control solenoid valve or a new unit. Tighten the IVT Control Solenoid Valve mounting bolts to torque spec.