The purpose of the cruise control system is to automatically maintain a vehicle speed set by the driver. When the cruise control is activated, speed is maintained or increased by means of an electronically controlled cable attached to the accelerator assembly. If the vehicle must be slowed to maintain the speed that was set by the driver, the cruise control system allows the throttle return spring to close the throttle.
If driving conditions require sudden acceleration after the cruise control has been set, speed can be increased in the normal manner by manually pressing the accelerator. The cruise control is disengaged if the brakes, or clutch, with manual transaxle, are applied.
The minimum speed for setting the cruise control is 29 km/h (18 mph). When cruise control is operating, the CRUISE indicator lamp is on in the instrument cluster.
The cruise control system is capable of monitoring internal software and hardware faults as well as external faults in the connectors and wire harness. If a fault is detected, cruise control is stopped immediately, and the program logic and hardware logic independently prevent the cruise control from opening the throttle.
The cruise control will function in temperatures ranging from -40°C to +85°C (-40°F to +185°F). Maximum temperature could cause the regulation properties to be out of tolerance, but the safety shutdown will still be operational under maximum temperature conditions. If high temperature interferes with cruise control operation, the actuator electromagnetic clutch will open, and the throttle return spring will close the throttle, unless the accelerator pedal is pressed.
Cruise Control Actuator
The cruise control actuator is a single component system. The electronic controls are combined in one housing with the mechanical components. The actuator is mounted in the passenger compartment.
The mechanical components of the cruise control actuator are listed below:
| • | Permanent field DC motor |
| • | Single stage belt transfer gearing |
| • | Spindle drive |
| • | Electromagnetic clutch |
| • | Clutch plate with cable attachment |
| • | End switches |
| • | Plastic housing with noise reduction cover |
| • | Damping unit for clutch plate slap |
The mechanical parts are not serviceable. The entire actuator must be replaced if it is mechanically defective.
The electronics of the cruise control system include the following items:
| • | A microprocessor which controls speed regulation and monitors input signals |
| • | A clutch activation circuit which energizes the clutch magnet to couple the DC motor to the control cable |
| • | A driver circuit which activates the DC motor in a clockwise or counterclockwise direction |
| • | A control unit for lamp activation |
The electronic parts are not serviceable. The entire actuator must be replaced if there is an electronic defect in one of the systems.
Cruise Control Switch
After the main switch is turned on and the neutral position of the lever switch is detected by the cruise control actuator, the following operations can be performed by using the cruise control lever switch:
Set
If the cruise control is ON and the minimum speed is 29 km/h (18 mph),the target speed can be set by selecting the SET button for at least 35 milliseconds. If SET is selected for more than 1 second, the cruise control will be activated in the COAST function. If the accelerator is pressed by the driver after the cruise control has been set, the previous target speed will be maintained when the accelerator is released.
Coast
If a target speed has been set and COAST is selected for at least 1 second, the throttle will return to idle, and the vehicle will coast. When the COAST switch is released, the current speed will be maintained as the new target speed. If the vehicle speed drops below 29 km/h (18 mph) while coasting, the cruise control will be disengaged.
Resume
If the cruise control is ON, and the system was disengaged by using the brake or clutch, exceeding the maximum speed, failing to maintain the minimum speed, or exceeding the target by more than 32.2km/h (20 mph), the last memorized speed can be reset by selecting RESUME if the time since disengagement is not greater than 5 seconds. The RESUME function is selected by switching to RESUME for at least 35 milliseconds. If the actual speed is above the target speed when RESUME is selected, the throttle will be allowed to return to idle until the target speed is achieved. RESUME can be canceled by selecting SET, and then the current speed will be maintained as the new target speed.
Accelerate
If the cruise control is ON, and the ACCEL switch is selected for more than 1 second, the vehicle will accelerate. When the switch is released, the current speed will be stored and used as the new target speed.
Tap-Up
If the cruise control has been set, and RESUME is selected again for 35 milliseconds to 1 second, the target speed will increase by 1.6 km/h (1 mph) for each time that the RESUME button was selected, or tapped.
Tap-Down
If the cruise control is already set and SET is selected for between 35 milliseconds to 1 second, the target speed will decrease by 1.6 km/h (1 mph) for each time that SET was selected, or tapped.
If the cruise control is turned OFF with the main switch, all cruise control functions are stopped, the actuator cable is driven toward idle, and the electromagnetic clutch for the cable actuator is opened. The cable actuator clutch is not opened immediately to accomplish a smooth transition in vehicle speed. If the cruise control is OFF for more than 5 seconds, the memorized target speed is erased.
