System Outline

The cruise control system is a constant vehicle speed controller with which it is possible to automatically adjust the opening of the engine throttle valve without depressing the accelerator pedal, but by operating a switch instead.

1. Set Operation 

   If the ON-OFF SW is turned on and the - SET SW is pushed while the vehicle speed is within the settable limit (Approx. 40 km/h, 25 mph to 200 km/h, 124 mph), a signal is input to TERMINAL CCS of the engine control module and the vehicle speed at the time the - SET SW is released will be stored in the engine control module as the set speed.

2. Set Speed Control 

   During cruise control driving, the engine control module compares the set speed stored in the engine control module with the actual vehicle speed which is being input into TERMINAL SPD of the engine control module from the combination meter, and controls the throttle body assembly to maintain vehicle at the set speed.

   If the actual speed is lower than the set speed, the ECU causes current from the throttle control motor to flow from TERMINAL M+ of the engine control module to TERMINAL 2 of the throttle body assembly then out TERMINAL 1 to TERMINAL M- of the engine control module. As a result, the motor in the throttle control motor is rotated to open the throttle valve to increase the vehicle speed. If the actual driving speed is higher than the set speed, current from the throttle body assembly flows from TERMINAL M- of the engine control module to TERMINAL 1 of the throttle control motor then out TERMINAL 2 to TERMINAL M+ of the engine control module.

   This causes the motor in the throttle body assembly to rotate to close the throttle valve to decrease the vehicle speed.

3. Coast Control 

   When driving with the cruise control active, while the - SET SW is on, the throttle control motor will be rotated to close the throttle valve and decrease the driving speed. The vehicle speed when the - SET SW is turned off is memorized, and the vehicle continues at the new set speed.

4. Accel Control 

   When driving with the cruise control active, while the + RES SW is held down, the throttle control motor is rotated to open the throttle valve and increase the driving speed.

   The vehicle speed when the + RES SW is released will be stored and the vehicle will continue at the new set speed.

5. Resume Control 

   If the vehicle speed is approximately 40 km/h (25 mph) or more and the cruise control was previously cancelled via the CANCEL SW, pushing the + RES SW will cause the vehicle to resume the speed set before the cancellation.

6. Manual Cancel Mechanism 

   If any of the following signals are received while driving with the cruise control active, the cruise control will be cancelled.

   * The clutch pedal is depressed (Cruise control clutch SW off). "Signal is not input to TERMINAL D of the engine control module" (M/T)

   * The shift lever is moved to a position other than "D" or "3rd" (Park/Neutral position SW except "D" or "3rd" position). (A/T)

   * The CANCEL SW is pressed (CANCEL SW on). "Signal input to TERMINAL CCS of the engine control module"

   * The ON-OFF SW is turned off "signal input to TERMINAL CCS of the engine control module".

   * The brake pedal is depressed (Stop lamp SW on).

7. Tap-Up Control Function 

   As long as the difference between the actual vehicle speed and the current set speed is less than 5 km/h (3 mph), the set speed can be increased in steps of 1.6 km/h (1 mph) by momentarily pressing the + RES SW (less than 0.6 seconds).

8. Tap-Down Control Function 

   As long as the difference between the actual vehicle speed and the current set speed is less than 5 km/h (3 mph), the set speed can be decreased in steps of 1.6 km/h (1 mph) by momentarily pressing the - SET SW (less than 0.6 seconds).

9. Auto Cancel Function 

   If any of the following operating conditions occurs while driving with the cruise control active, the set speed will be erased and the cruise control will be released, (ON-OFF SW turns off).

   When this occurs, the ignition SW must be turned off once before the ON-OFF SW will turn on again.

   * When an abnormality is found in the stop lamp SW input circuit.

   * When an abnormality is found in the cancel circuit.

   If any of the following operating conditions occurs while driving with the cruise control active, the set speed will be erased and the cruise control will be released. (ON-OFF SW turn off).

   When this occurs, the cancel state will be cleared as the ON-OFF SW will turn on again.

   * When an abnormality is found in the electronic throttle parts.

   * There is an open circuit in the stop lamp SW.

   * There is a momentary interruption of vehicle speed signal.

   * There is a short circuit in the stop lamp SW.

10. Shift-Down Control Function 

    When the vehicle climbs a hill while running under cruise control, the gear may be shifted down by the A/T control. When the hill climb is judged to have finished, based on the throttle opening information, the gear is shifted up after a set time. If the gear is shifted down during acceleration or resume control, the gear is shifted back up after the acceleration or resume control ends.