Cruise Control: Description and Operation

Current is applied at all times through STOP fuse to TERMINAL 1 of cruise control ECU and to TERMINAL 1 of stop light switch, through the DOME fuse to TERMINAL 15 of the cruise control ECU.

With the ignition switch turned ON, current flows through GAUGE fuse to C-3 of cruise control indicator light, and also through the ECU-IG fuse 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 flows to TERMINAL 13 of cruise control ECU --> GROUND, and the cruise control system is ready for operation.

At the same time, current flowing through the GAUGE fuse flows to TERMINAL C-3 of cruise control indicator light --> TERMINAL A-3 --> 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 (and if the vehicle speed is within the set limit of approx. 36 kph, 22 mph to 200 kph, 124 mph), a signal is input to TERMINAL 18 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 vehicle 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 7 of cruise control actuator --> TERMINAL 8 --> 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 8 of cruise control actuator --> TERMINAL 7 --> 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 vehicle 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 vehicle 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. 36km/h, 22mph) after canceling the set speed by the cancel switch, pushing the resume switch will cause the vehicle to resume the speed set before cancellation.

6. CANCEL MECHANISM
If any of the following operations occurs during cruise control operation, the magnetic clutch of the actuator motor turns OFF and the motor rotates to close the throttle valve and the cruise control is released.

^ Depressing the brake pedal (stop light switch ON). "signal input to TERMINAL 16 of ECU"
^ Push the main switch (main SW OFF). "signal input to TERMINAL 19 of ECU".
^ Push the cancel switch (cancel switch ON). "signal input to TERMINAL 18 of the ECU"
^ Placing the shift lever in "N" position (park/neutral position SW ON) . The signal is input to TERMINAL 2 of ECU