Cruise Control: Description and Operation
DESCRIPTIONThe speed control system maintains the vehicle at a driver's selected speed over normal driving conditions, without the need for constant surveillance of the speedometer and continuous driver use of the throttle pedal.
Once engaged and set the speed control system will control the position of the throttle over a wide range of movement from idle to full throttle to maintain the speed set under different conditions.
SYSTEM COMPONENTS
Throttle actuator
A vacuum operated device containing bellows attached to the throttle by a mechanical linkage.
Electronic Control Unit (ECU)
A device containing a microprocessor and associated electronic circuits which evaluates the signal provided by the drivers controls, the pedal switches and road speed sensors. It then transmits signals to a vacuum control unit in order to control the vehicle speed. It also retains in memory the speed setting.
Vacuum pump and regulator valve
An assembly which increases and decreases the vacuum system pressure depending on signals received from the ECU.
Dump valve
A device which vents the vacuum system pressure to atmosphere when braking or the throttle returns to idle.
Operating switches
The system is controlled by a centre console mounted master switch and a resume button on the end of the combination switch stalk. A brake switch disengages the system.