Cruise Control System Description

Cruise control is a speed control system that maintains a desired vehicle speed under normal driving conditions. However, steep grades up or down may cause variations in the selected speeds. The electronic cruise control system has the capability to CRUISE, COAST, RESUME SPEED, ACCELERATE, and TAP-UP or TAP-DOWN.

With cruise control you can maintain a speed of about 40 km/h (25 mph) or more without keeping your foot on the accelerator. When the driver applies the brakes, presses the clutch pedal or turns off the on/off switch, the cruise control turns off.

The main parts of the cruise control system are the following components:
^ The cruise control module assembly
^ The function control switches
^ The vehicle speed sensor (VSS)
^ The cruise control release (brake) switch assembly
^ The cruise control (clutch) switch assembly
^ The stoplamp switch assembly

The cruise control system uses a cruise control module assembly to obtain the desired vehicle cruise operation. Two important components in the module assembly help to do this. The first is an electronic controller, and the second is an electric stepper motor. The electric controller monitors vehicle speed and operates the electric stepper motor. The electric stepper motor moves a strap that is attached to the cruise control cable which moves the throttle linkage. The stepper motor operates in response to the electronic controller to maintain the desired cruise speed. The cruise control module assembly contains a low speed limit which will prevent system engagement below a speed of 40 km/h (25 mph). The operation of the electronic controller is controlled by function control switches located on the multi-function lever. The cruise control module assembly has an electronic controller and an electric stepper motor to vary the throttle in each different cruise control mode. The module assembly is not serviceable.

The cruise control function switch includes the ON/OFF, SET/COAST and R/A (resume/accelerate) switches. The switch assembly provides driver control of the cruise control system.

The cruise control release (brake) switch, the cruise control (clutch) switch and the stoplamp switch assemblies are used to disengage the cruise control. The cruise control release (brake) switch assembly and the stoplamp switch assembly, mounted on the brake pedal bracket, disengage the system electrically when the driver presses the brake pedal. The cruise control (clutch) switch, mounted on the clutch pedal bracket, will also disengage the system when the driver presses the clutch pedal. When either pedal is pressed, the speed of the vehicle is stored in the cruise module memory.

The Vehicle Speed Sensor (VSS) is mounted to the automatic or manual transaxle assembly and produces an AC signal. The frequency of this signal is proportional to the speed at which the automatic or manual transaxle assembly output shaft rotates, which in turn is proportional to the speed of the vehicle. The AC signal is supplied to the Powertrain Control Module (PCM) where it is converted to the number of pulses per mile per second to determine vehicle speed. The signal is then sent to the cruise control module assembly and the speedometer assembly at a rate of 4000 pulses per mile.