The RTD system is bi-state real time damping system. The
Suspension Control  module controls the suspension damper  solenoids and suspension
position sensors, along with parts of the automatic  level control (ALC) system
and electronic variable orifice (EVO) power steering  system.
The Automatic Level Control system consists of the following:
|     •  | Suspension Control Module | 
 
|     •  | Compressor/Leveling Module | 
 
The objective of the Automatic Level Control System is to provide constant
ride height at all load conditions. The Suspension Control module monitors
body-to-wheel height, and vehicle speed.
The Suspension Control module will use the rear body-to-wheel displacements
and vehicle speed inputs to keep the rear trim height of the vehicle at its
desired  level.