Cruise Control: Description and Operation

The cruise control system uses mechanical, electrical and vacuum operated devices to maintain vehicle speed at a setting selected by the driver.

SYSTEM DESCRIPTION

The cruise control unit receives command signals from the cruise control switch. It receives information about operating conditions from the brake light switch, the vehicle speed sensor, the clutch interrupt switch (manual transmission), and the neutral switch.

The cruise control unit sends operational signals to the devices that regulate the throttle position. The throttle position maintains the selected vehicle speed. The control unit compares the actual speed of the vehicle to the selected speed and uses the result of that comparison to open or close the throttle.

The brake light switch releases the system's control of the throttle at the instant the driver depresses the brake pedal. The switch sends a signal to the control unit when the brake pedal is depressed; the control unit responds by allowing the throttle to close. The clutch interrupt switch or the neutral switch sends a disengage signal input to the control unit that also allows the throttle to close.

SYSTEM OPERATION

The cruise control system will set and automatically maintain any speed above 25 mph (4O kph). To set, make sure that the cruise control switch is in the ON position. After reaching the desired speed, press the set switch. The cruise control unit will receive a set signal input and activate the cruise control actuator.

Pushing the cruise control switch to OFF cancels the cruise control system. This removes power to the control unit and erases the set speed from memory. If the system is disengaged temporarily by the brake light switch, clutch interrupt switch, or neutral switch and the vehicle speed is still above 20 mph, press the resume switch. With the resume switch depressed and the set memory retained, the vehicle automatically returns to the previous set speed.


For gradual acceleration without depressing the accelerator pedal, push the resume/accel switch down and hold it there until the desired speed is reached. This will send an acceleration signal input to the control unit. When the switch is released, the system will be reprogrammed for the new speed. To slow the vehicle down, depress the set/coast switch. This will send a deceleration signal input to the control unit, causing the vehicle to coast until the desired speed is reached. When the desired speed is reached, release the set/coast switch. This will reprogram the system for the new speed.