Circuit Description

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Cadillac Escalade EXT. However, it is still accessible from the selected car via links, so may be relevant.

The Body Control Module (BCM), or Electronic Suspension Control (ESC) Module, vehicles equipped with Real Time Damping (RTD), provides a pulse width modulated (PWM) supply circuit, and a control circuit to the Electronic Variable Orifice (EVO) solenoid. The supply circuit is used to regulate the current to the solenoid which controls the size of the power steering pump's output fluid orifice, depending on vehicle speed. This results in an increase or decrease in steering effort. The control circuit is used to disable the EVO outputs to provide full steering assist when a malfunction is detected.

NOTE: The BCM/ESC stores the DTCs scan tool data and special functions. However, the scan tool menu to access variable effort steering is located in chassis.