System Description
Cruise control system that maintains a desired vehicle speed under normal driving conditions. However, steep grades up or down may cause variations in selected speeds. Cruise control system has capability to perform the following actions:
- Set cruise speed
- Cruise
- Coast
- Resume speed
- Accelerate
- Tap-up
- Tap-down
Cruise control circuit contains the following components:
- Cruise Control Servo
- Cruise Control Module
- Cruise Control Switch
- Vehicle Speed Sensor (VSS)
Cruise control module and cruise control servo are 2 main components that allow system to control and maintain desired vehicle speed. Cruise control module monitors vehicle speed and provides cruise control servo with necessary commands to maintain or change vehicle speed in response to inputs from cruise control switch. In response to control module, cruise control servo moves a connecting arm. Connecting arm is attached to cruise control cable. Cable moves throttle linkage in order to vary throttle position. This action maintains desired cruise speed.
Cruise control module contains a low speed limit that will prevent system engagement below a minimum speed of approximately 25 MPH. Cruise control module is controlled by cruise control switch. Cruise control is in Standby Disabled until all of conditions that are inconsistent with cruise control operation are cleared. Cruise control operation is disengaged when cruise control module receives a cancel signal from brakelight switch, cruise control switch, Park/Neutral Position (PNP) switch (on vehicles equipped with an automatic transmission) and cruise control release switch (on vehicles equipped with an manual transmission). Upon receiving a cancel signal, cruise control de-energizes magnetic clutch inside cruise control servo. With magnetic clutch de-energized, cruise control servo and connecting arm are no longer mechanically connected and throttle returns to idle position.