System Description

The vehicle speed control system consists of the following components:
^ Anti-lock brake control module
^ Deactivator switch
^ Lighting Control Module (LCM)
^ Message center display
^ Speed control actuator cable
^ Speed control actuator switch
^ Speed control servo

The speed control system is designed to maintain vehicle speed above 48 km/h (30 mph). After the ON switch is depressed, depressing the SET/ACCEL switch will activate the speed control servo. To increase a set speed, either depress and hold for continuous acceleration, or momentarily tap the SET/ACCEL switch for 1.6 km/h (1 mph) acceleration increments. To decrease a set speed, depress and hold the COAST switch until the target speed is reached, or momentarily tap the COAST switch for 1.6 km/h (1 mph) deceleration increments. When the speed control system has been disabled by tapping the brake pedal, the RESUME switch can be depressed and the vehicle will return to the original set speed if the vehicle is traveling over 48 km/h (30 mph) and the OFF switch has not been depressed. When the instrument panel is in metric mode, the tap up and down will change the set speed by 2 km/h per tap. The speed control system will only maintain a set speed above 48 km/h.

The deactivator switch is provided as an additional safety feature. Normally, when the brake pedal is depressed, a message from the Standard Corporate Protocol (SCP) link to the speed control servo will deactivate the system. Under increased brake pedal effort, the deactivator switch will open and remove power to the speed control servo, releasing the throttle independent of the speed control servo.

The air bag sliding contact provides the electrical interface between the steering column wiring and the speed control actuator switches in the steering wheel.
The inputs to the speed control servo are:
^ SCP link. The speed control servo communicates with other control modules using SCP link. The vehicle speed, brake pedal position, throttle position, rpm, and PRNDL status is retrieved by the speed control servo from the SCP link.
^ Speed control actuator switches.
^ Deactivator switch.

The outputs of the speed control servo are:
^ SCP link. The speed control servo sends an output message through the SCP link to indicate whether the speed control system is ON, OFF, ENGAGED, or DISENGAGED.
^ Speed control actuator cable controlling the throttle position.