Cruise Control Description
CRUISE CONTROL DESCRIPTION
Cruise control is a speed control system which 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" and "tap-down".
The main parts of the cruise control system are the mode control switches, controller (module), servo unit, speed sensor, vacuum supply, electrical and vacuum release switches, and electrical harness.
The cruise control system uses vacuum to operate a throttle servo unit. The servo unit maintains a desired vehicle speed by trapping vacuum in the servo unit at the proper servo position. The controller monitors vehicle speed and servo position and operates the vacuum and vent valves in the servo to maintain desired speed. The controller contains a low speed limit which will prevent system engagement below a minimum speed about 25 mph. The operation of the controller is controlled by mode control switches located in the end of the directional signal lever. To disengage the system, two release switches are provided. An electrical release switch mounted on the brake pedal bracket (and clutch pedal bracket on vehicles equipped with manual transmission) disengages the system electrically when the brake pedal (or clutch pedal) is depressed. A vacuum release valve, mounted on the brake pedal bracket, vents the trapped vacuum in the servo to atmosphere when the brake pedal is depressed, allowing the servo unit to quickly return the throttle to idle position.
OFF/ON/RESUME/ACCEL SWITCH
The Off/On/Resume/Accel Switch has three positions. This switch turns the cruise control system ON and OFF and also returns cruise control operation to the last speed setting when MOMENTARILY moved towards the R/A position after braking. (Do not hold the slider in the R/A position, release it immediately.) If the slider is held in the R/A position for more than one second, the system reverts to the Accel mode. To accelerate the vehicle, move the slider switch to the R/A position and hold it there until the vehicle reaches the desired increased speed. When the slider switch is released, the speed the vehicle accelerated to becomes the new cruise speed. In order to use the Accel mode, the cruise OFF/ON/Resume/Accel switch must be in the "On" position and the vehicle must be above the low speed lockout (25 mph). The slide switch can also be used to "tap-up" vehicle speed. In order to do this the cruise must be engaged and operating. "Tapping-up" is done by quickly pressing the slide switch toward the R/A position and quickly releasing it, or "tap" the lever. Do not hold the lever in the R/A position or the system will revert to the Accel mode. "Tap-up" is a function in which cruise speed can be increased by 1 mph increments (one tape = 1 mph increase) up to ten times, after 10 times the system must be reset to a new speed to continue this function.
SET/COAST BUTTON SWITCH
The cruise control Set/Coast Switch, located in the end of the turn signal lever, has two positions - "Normal" and "Depressed."
The Set Position - With the button switch depressed and then released, vehicle speed must exceed the low speed limit point, and the Off/On/Resume/Accel Switch must be in the ON position) the cruise speed will be set at the particular speed the vehicle was at when the button was released. Vehicle cruise speed will be within ± 1 mph of the actual speed when engaged. The system will cruise until either the Off/On/Resume/Accel Switch is moved to OFF, the ignition switch is turned off, and/or the Set/Coast Button is pushed in fully and held. Pushing the brake pedal (or clutch pedal) releases the cruise but not the resume capability.
The Coast (Trim) Position - With the button switch fully depressed, the driver can raise or lower his control speed. To increase control speed, the driver would accelerate to a new speed, fully depress the switch (controller releases previously set speed) and release the button. Upon releasing the button a new speed is set. An increased control speed can also be more easily set by the Off/On/Resume/ Accel Switch as previously described. To decrease cruise speed, the button switch is held in (depressed position) disengaging the cruise system, and allowing the throttle to return to the idle position. When the vehicle has slowed to the desired lower cruise speed, releasing the switch will reengage the system.
The "Tap-Down" Position - In order to do this the cruise must be engaged and operating "Tapping-down" is done by quickly pressing the Set/Coast Button to the depressed position and quickly releasing it, or "tap" the button. Do not hold the button in the depressed position or the system will revert to the "coast" mode. "Tap-down" is a function in which cruise speed can be decreased by 1 mph increments (one tap = 1 mph decrease). The system can "tap-down" until it reaches the low speed lockout (25 mph), after this cruise will not operate.
The accelerator may be depressed at any time to override the cruise system. Release of the accelerator will return the car to the previous set cruise speed.
NOTICE: To keep the vehicle under control, and to prevent possible vehicle damage, it is not advisable to use the Cruise Control on slippery roads. It is not recommended to use the cruise control in conditions such as on winding roads or in traffic to heavy or varying volume. When traveling down a steeply graded hill, the cruise control should be disengaged by depressing the brake pedal lightly. The transmission can then be shifted into a lower gear range to help control vehicle speed.