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 perform the following functions:
The following list indicates the main parts of the cruise control system:
• | The cruise control module assembly |
• | The function control switches |
• | The vehicle speed sensor (VSS) |
• | The cruise control release switch |
• | The stoplamp switch assemblies |
The cruise control system uses a cruise control module assembly in
order 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 in order to maintain the desired cruise speed. The cruise control
module assembly contains a low speed limit which will prevent system engagement
below a minimum speed of 40 km/h (25 mph). The operation of
the electronic controller is controlled by function control switches. The
function control switches are located on the steering wheel.
The cruise control module assembly has an electronic controller and
an electric stepper motor in order to vary the throttle in each different
cruise control mode. The module assembly is not serviceable.
The cruise control function switches include the ON/OFF, SET/COAST and
R/A (resume/accelerate) switch. The steering wheel switches provide driver
control of the cruise control system.
The cruise control release switch and stoplamp switch assemblies are
used in order to disengage the cruise control. A release switch assembly and
a stoplamp switch assembly are mounted on the brake pedal bracket. These
assemblies electrically disengage the system when the driver presses the brake
pedal. The speed of the vehicle at brake actuation will be stored in the
memory of the cruise module.
The vehicle speed sensor (VSS) is mounted to the automatic transaxle
assembly and produces an AC signal. The frequency of this signal is proportional
to the speed at which the automatic 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). The PCM converts the
number of pulses per mile, per second in order to determine the 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.
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, or turns off the on/off switch, the cruise
control turns off.