GM Service Manual Online
For 1990-2009 cars only

CVRSS Damper High-Side

The high-side of each damper solenoid is connected to the CVRSS control module. The control module controls the voltage on these lines via a relay (RTD Body Relay).

CVRSS Damper Low-Side

The current delivered to each actuator is controlled by a method known as Pulse-Width Modulation (PWM), in which the battery voltage command to the actuator is switched on and off at a high frequency (2.0 kilohertz). The actuator current is a function of the duty cycle, or percentage of time that the battery voltage is applied. The default damper state (with no battery voltage, and thus no current, provided to the attached solenoid actuator) is minimum damping force. Higher levels of damping forces are developed by providing correspondingly higher current levels, relating to higher percentages of PWM duty cycle.

ICCS2 Datalink Outputs (Left and Right)

A measure of the road surface is sent from the CVRSS control module to the EBTCM at four discrete levels via two data lines (circuits 790 and 791). The EBTCM uses this information to detect rough road conditions while braking, eliminating false, unwanted ABS cycling. This allows for more aggressive braking when stopping on rough roads.

ICCS2 data is passed from the CVRSS control module to the EBTCM via a Pulse-Width Modulation (PWM) method at a frequency of 333 Hertz.

Damper Control Relay (RTD Body Relay)

The high-side of the relay coil is connected to battery voltage through a fuse. The low-side of the relay coil is connected to the Damper High-Side Relay Enable line of the CVRSS control module.

ELC Compressor Relay

The high-side of the relay coil is tied to ignition through a fuse. The low-side of the relay coil is connected to the Compressor Relay Enable line of the CVRSS control module. The CVRSS control module switches the low-side to ground when compressor activity is required.

ELC Exhaust Valve

The high-side of the exhaust coil is tied to battery and the low-side is connected to the Exhaust Valve Enable line of the CVRSS control module. The CVRSS control module switches this low-side to ground when exhaust or compressor activity is required.