Cruise Control: Description and Operation

Current is applied at all times through STOP fuse to TERMINAL 2 of stop light switch.
With the ignition switch turned to ON, the current flows through GAUGE fuse to TERMINAL 12 of cruise control indicator light. The current through ECU-IG fuse flows to TERMINAL 14 of cruise control ECU.
When the ignition switch is ON and the cruise control main switch is turned ON, a signal is input from TERMINAL 15 of cruise control main switch to TERMINAL 19 of cruise control ECU. as a result. the cruise control ECU functions and the current to TERMINAL 14 of cruise control ECU to TERMINAL 13 of cruise control ECU --> GROUND, and the cruise control system is in a condition ready for operation.
At the same time, the current through the GAUGE fuse flows from TERMINAL 12 of cruise control indicator light --> TERMINAL 15 --> TERMINAL 7 of cruise control ECU --> TERMINAL 13 --> to GROUND, causing the cruise control indicator light to light up, indicating that the cruise control is ready for operation.

1. SET OPERATION
When the cruise control main switch is turned ON and the set switch is pushed with the vehicle speed within the set limit (Approx. 40Kph, 25mph to 200Kph, 124mph), a signal is input to TERMINAL 19 of the cruise control ECU and the vehicle speed at the time the set switch is released is memorized in the ECU as the set speed.

2. SET SPEED CONTROL
During cruise control driving, the ECU compares the set speed memorized in the ECU with the actual vehicle speed input into TERMINAL 20 of the cruise control ECU from the speed sensor, and controls the cruise control actuator to maintain the set speed.
When the actual speed is lower than the set speed, the ECU causes the current to the cruise control actuator to flow from TERMINAL 12 --> TERMINAL 6 of cruise control actuator --> TERMINAL 7 --> TERMINAL 11 of cruise control ECU. As a result, the motor in the cruise control actuator is rotated to open the throttle valve and the throttle cable is pulled to increase the vehicle speed. When the actual driving speed is higher than the set speed, the current to cruise control actuator flows from TERMINAL 11 of ECU --> TERMINAL 7 of cruise control actuator --> TERMINAL 6 --> TERMINAL 12 of cruise control ECU.
This causes the motor in the cruise control actuator to rotate to close the throttle valve and return the throttle cable to decrease the vehicle speed.

3. COAST CONTROL
During the cruise control driving, while the coast switch is ON, the cruise control actuator returns the throttle cable to close the throttle valve and decrease the driving speed. The vehicle speed when the coast switch is turned off is memorized and the vehicle continues at the new set speed.

4. ACCEL CONTROL
During cruise control driving, while the Accel switch is turned ON, the cruise control actuator pulls the throttle cable to open the throttle valve and increase the driving speed. The vehicle speed when the Accel switch is turned off is memorized and the vehicle continues at the new set speed.

5. RESUME CONTROL
Unless the vehicle speed falls below the minimum speed limit (Approx. 40Kph) after canceling the speed by the cancel switch, pushing the resume switch will cause the vehicle to resume the speed set before cancellation.

6. MANUAL CANCEL MECHANISM
If any the following operations occurs during cruise control operation, the magnetic clutch of the actuator turns off and the motor rotates to close the throttle valve and the cruise control is released.
^ Depressing the clutch pedal (cruise control clutch switch ON). "signal input to TERMINAL 2 of ECU" (M/T) shift lever at "N" position (Neutral start switch ON). "signal input to TERMINAL 2 of the ECU" (A/T)
^ Depressing the brake pedal (stop light switch ON). "signal input to TERMINAL 16 of ECU"
^ Push the cancel switch (cancel switch ON). "signal input to TERMINAL 18.

7. AUTO CANCEL FUNCTION
A. If any of the following operate conditions occurs during cruise control operation, the set speed is erased, current Flow to magnetic clutch is stopped and the cruise control is released. (Main switch turns off). When this occurs, the ignition switch must be turned off once before the main switch will turn ON.
^ Over current to transistor driving motor and/or magnetic clutch.
^ When the current continued to flow to the motor in side the actuator in the throttle valve "Open" direction
^ Open circuit in magnetic clutch.
^ Momentary interruption of vehicle speed signal.
^ The resume switch is already ON when the main switch is turned ON.
^ Short circuit in cruise control switch.
^ Motor does not operate despite the motor drive signal being output.
B. If any of the following conditions occur during cruise control operation, the set speed is erased and the cruise control is released. (the power of magnetic clutch is cut off until the set switch is "ON" again.)
^ When the vehicle speed fails below the minimum limit, Approx. 40Kph (25mph)
^ When the vehicle speed falls more than 16Kph (10mph) below the set speed, e.g. ON an upward slope.
^ When power to the cruise control system is momentarily cut off.
C) If any of the following conditions occurs during cruise control operation, the cruise control is released.
^ Open circuit for TERMINAL 16 of cruise control ECU.