Cruise Control: Description and Operation

The cruise control system uses mechanical, electrical, and vacuum-operated devices to maintain vehicle speed at a setting selected by the driver.

System Description
The cruise control unit receives command signals from the cruise control switch. It receives information about operating conditions from the brake switch, the vehicle speed sensor, the clutch switch (M/T), and the automatic transmission mode switch and powertrain control module (A/T).

The cruise control unit sends signals to the devices that regulate the throttle position to maintain the selected vehicle speed. The control unit compares the actual speed of the vehicle to the selected speed, and, based on the result of that comparison, opens or closes the throttle.

The brake switch releases the system's control of the throttle at the instant the driver presses the brake pedal. The switch sends a signal to the cruise control unit and the cruise control unit responds by allowing the throttle to close. The clutch switch and the automatic transmission mode switch can also send a disengage signal to the cruise control unit that allows the throttle to close.

System Operation
The cruise control system will set and automatically maintain any speed above 25 mph (40 km/h). To set it, make sure the cruise control main switch is in the ON position and, after reaching the desired speed, press the set switch. The cruise control unit will receive a "set" signal and activate the cruise control actuator.

Pushing the cruise control main switch to OFF cancels the cruise control by removing power to the cruise control unit which erases the set speed from memory. The cruise control system also disengages when cruising speed is lower than the preset speed by at least 12.5 mph (20 km/h). If the system is disengaged temporarily by the brake switch, clutch switch, or the automatic transmission mode switch, and vehicle speed is still above 16 mph (25 km/h), you can turn the knob to the resume/accel position to reset the system. The set speed is still in memory so the vehicle automatically return to that speed.

To gradually accelerate beyond the set speed without pressing the accelerator pedal, turn the knob to the resume/accel position and hold it there until the desired speed is reached. This will send an acceleration signal to the cruise control unit. When you release the switch, the system will be reprogrammed for the new speed. Quickly turning and releasing the resume/accel switch allows you to "tap up" up the preset cruising speed. Each turn-and-release increases the preset speed by 1 mph (1.6 km/h). The preset speed can be increased by up to 10 mph (16 km/h) this way.

To slow the vehicle down, press the set/coast switch button. This will send a deceleration signal to the cruise control unit, causing the vehicle to coast. When the desired speed is reached, release the set/coast switch. This will reprogram the system for the new speed. Quickly depressing and releasing the set/coast switch button allows you to "tap down" the preset cruising speed. Each tap decreases the preset speed by 1 mph (1.6 km/h). The preset speed can be decreased to a minimum of 25 mph (40 km/h) this way.

The circuit consists of the starter switch, cruise control main switch, cruise control switch, cruise control unit, pump & actuator, brake switch, clutch switch (M/T), mode switch (A/T), vehicle speed sensor (incorporated into the speedometer) and indicator light.

The cruise control keeps the vehicle running at a fixed speed until a signal canceling this fixed speed is received. When the main switch "AUTO CRUISE" is turned on with the vehicle in the running mode, the battery voltage is applied to the control unit. When a signal from the control switch is input to the control unit while the vehicle is in this state, the cruise control actuator is activated to operate the system.

Also, while the system is operating, the "AUTO CRUISE" indicator light in the meter assembly lights up.

1. SET/COAST SWITCH FUNCTION
1. Set function: When the SET/COAST switch is pressed and released with the main switch ON, the speed at which the vehicle is running at that moment is stored in the memory', and the vehicle automatically runs at the stored speed.
2. Coast-down function: When the SET/COAST switch is kept ON while the vehicle in running, the vehicle decelerates during that time. The speed at which vehicle is running when the control switch is turned off is stored in the memory', and the vehicle automatically returns to the stored speed.
3. Tap-down function: When the SET/COAST switch is turned on and off instantaneously while the vehicle is running, the vehicle decelerates a mile for each ON/OFF operation. The vehicle speed at which the vehicle was running when the SET/COAST was turned off last is stored in the memory', and the vehicle automatically returns to this stored speed.

2. RESUME/ACCEL SWITCH FUNCTION
1. Resume function: When the RESUME/ACCEL switch is turned ON/OFF after the system is temporarily deactivated by pressing the brake or clutch pedal while the vehicle is running, the vehicle resumes the speed stored before the system was released, and the vehicle automatically runs at the stored speed.
2. Accelerate function: When the RESUME/ACCEL switch is kept on after the system is released completely, the vehicle accelerates its speed during that time. The vehicle speed at which the vehicle was running when the switch was turned OFF is stored in the memory', and the vehicle automatically returns to this speed.
3. Tap-up function: When the RESUME/ACCEL switch is turned on and off instantaneously while the vehicle is running, the vehicle decelerates a mile for each ON/OFF operation. The vehicle speed at which the vehicle was running when the switch was turned OFF last is stored in the memory, and the vehicle automatically returns to this stored speed.

3. CANCEL FUNCTION
1. Temporary cancellation:
^ When the brake pedal is pressed.
^ When the clutch pedal is pressed. (M/T)
^ When the select lever is shifted to any position other than "D", "3", "2" or "L".(A/T)
^ When the cancel switch is operated.
^ When the vehicle speed exceeds about 12.5 mph over the vehicle speed stored in the memory.
^ Turning the RESUME/ACCEL switch will return the vehicle to the speed stored in the cruise control memory.
2. Complete cancellation:
^ When the starter switch or the main switch is turned OFF.
^ When the fail-safe function is activated.
^ When the vehicle speed is about 24 mph.