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 on the instrument panel instead.

1. Set Operation 

   When the ON-OFF switch is turned on and the - SET switch is pushed and the vehicle speed is within the allowable speed limits (Approx. 40 km/h, 25 mph to 200 km/h, 125 mph), a signal is input into TERMINAL CCS of the ECM and the vehicle speed at the time the - SET switch is released is stored in the ECU as the set speed.

2. Set Speed Control 

   When driving with the cruise control active, the ECU compares the set speed stored in the ECU with the actual vehicle speed that is being received by TERMINAL SPD of the ECM from the combination meter assembly, and adjusts the throttle body assembly to maintain the vehicle at the set speed.

   When the actual speed is lower than the set speed, the ECU sends current from TERMINAL M+ of the ECM to TERMINAL 2 of the throttle body assembly and out TERMINAL 1 to TERMINAL M of the ECM. As a result, the motor in the throttle control motor rotates to open the throttle valve, which increases the vehicle speed. Conversely, when the actual driving speed is higher than the set speed, current is sent from TERMINAL M of the ECU to TERMINAL 1 of the throttle control motor then out TERMINAL 2 to TERMINAL M+ of the ECM.

   This causes the motor in the throttle body assembly to rotate and close the throttle valve, which decreases the vehicle speed.

3. Coast Control 

   When driving with the cruise control active, if the - SET switch is pressed and held down, the throttle control motor is rotated to close the throttle valve and decrease the driving speed slowly and continuously. The vehicle speed when the - SET switch is released is stored, and the vehicle continues at the new set speed.

4. Accel Control 

   When driving with the cruise control active, while the + RES switch is pressed and held down, the throttle control motor is rotated to open the throttle valve and increase the driving speed slowly and continuously. The vehicle speed when the + RES switch is released is stored, and the vehicle continues at the new set speed.

5. Resume Control 

   If the vehicle speed is approximately 40 km/h (25 mph) or above and the cruise control was cancelled with the CANCEL switch, pushing the + RES switch will cause the vehicle to resume the speed at which it was set before the cancellation.

6. Manual Cancel Mechanism 

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

   * The clutch pedal is depressed (Clutch switch assembly off). "Signal is not input to TERMINAL D of the ECU" (M/T)

   * Placing the shift lever in any positions except the "D" position. (Park/Neutral position switch except "D" position) (A/T)

   * The CANCEL switch is pushed (CANCEL switch on). "Signal input to TERMINAL CCS of the ECU"

   * The ON-OFF switch is turned off. "Signal input to TERMINAL CCS of the ECU"

   * The brake pedal is depressed. (Stop light switch assembly on)

7. Tap-Up Control Function 

   When the difference between the actual vehicle speed and the set speed is less than 5 km/h (3 mph), the set speed can be increased in 1.6 km/h (1 mph) steps by briefly (0.6 seconds) pressing the + RES switch.

8. Tap-Down Control Function 

   When the difference between the actual vehicle speed and the set speed is less than 5 km/h (3 mph), the set speed can be decreased in 1.6 km/h (1 mph) steps by briefly (0.6 seconds) pressing the - SET switch.

9. Auto Cancel Function 
   1. 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 deactivated, (ON-OFF switch turns off).

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

      * When an abnormality is found in the stop light switch assembly input circuit.

      * When an abnormality is found in the cancel circuit.

   2. 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 deactivated. (ON-OFF switch turns off).

      When this occurs, the cancel state is cleared but the ON-OFF switch will be able to be activated again without restarting the vehicle.

      * When an abnormality is found in electronic throttle parts.

      * Open circuit in the stop light switch assembly.

      * Momentary interruption of vehicle speed signal.

      * Short circuit in the stop light switch assembly.

      * When the vehicle speed falls below the low speed limit.

      * When the vehicle speed falls to 16 km/h (10 mph) less than the set speed.

      * During VSC operation.