Overview
The semi-active suspension dampening provides improved handling, comfort and stability by continuously adjusting the adaptive shock absorber force to the current road and driving conditions.
Vehicle Dynamic Suspension
The VDM is connected to the HS-CAN to communicate with the ABS module, the PCM and other systems. With the information received the VDM monitors the heave, roll, pitch, cornering, braking and acceleration of the vehicle. Based on that information the VDM calculates the best action for each valve solenoid.
Component Description
Vehicle Dynamics Module (VDM)
The VDM monitors all sensor inputs and all HS-CAN messages that relate to the vehicle dynamic suspension and then directly controls the valve solenoids. The VDM sends an individual electrical current to each valve solenoid to control the amount of damping required.
When a new VDM is installed, the module must be programmed with the vehicle configuration information. For additional information on module programming, refer to Section 418-01 .
When one of the following components is installed new, the VDM requires calibration.
VDM
Suspension height sensor
Front lower control arm
Front strut assembly
Rear lower control arm
Rear upper control arm
Rear wheel knuckle
The calibration procedure is required for the system to learn the "zero-position" of the vehicle which means the vehicle must be on a level surface, must not be moving and cannot contain any passengers or cargo. The calibration procedure is carried out using a scan tool.
Height Sensor
The height sensor uses a potentiometer to send a variable amount of voltage back to the VDM . The sensor has 3 circuits, one circuit is for the 5 volt sensor supply, one circuit is for sensor ground and one circuit is for the sensor output.
Valve Solenoid
The VDM uses a PWM output to control the valve solenoid. The solenoid will open or close the valve depending on the amount of current supplied by the VDM . The higher the current, the more the valve is opened, resulting in a "firm" suspension feel.
