Cruise Control: Description and Operation

CRUISE CONTROL SYSTEM OPERATION
The Cruise Control System works a mechanical linkage to the throttle by means of a Vacuum Motor. This is a diaphragm moved by a vacuum applied to one side. A solenoid driven valve connects the Vacuum Motor to a vacuum tank. Another solenoid valve vents the vacuum. The Cruise Control Module controls the Vacuum Motor and the throttle by pulsing these solenoid valves "ON" and "OFF."

VEHICLE SPEED INPUT
One input to the Cruise Control Module is the vehicle speed. This input comes from the Vehicle Speed Sensor. The Vehicle Speed Sensor is mounted on the Transaxle. If the actual speed signal is different from the speed that was set into and remembered by the Cruise Control Module, the Cruise Control Module pulses the solenoids to change the vacuum and return the vehicle to the set speed.

ADDITIONAL INPUTS
Other inputs to the Cruise Control Module are from the Resume/Accel Switch and the Set/Coast Switch. A disengage input to the Cruise Control Module comes from the Stoplamp/Cruise Brake Switch.

CRUISE CONTROL MODULE OUTPUTS
The two outputs of the Cruise Control Module operate the coils of the vacuum valve and the vent valve. Both valves are found in the Cruise Control Servo. These valves move the throttle by means of the Vacuum Motor. The Servo Position Sensor coil senses the position and motion of the Vacuum Motor. It feeds this information back to the Cruise Control Module to provide smooth performance while the vehicle is in Cruise Control.