CRUISE CONTROL SYSTEM SYSTEM DESCRIPTION


  1. CRUISE CONTROL SYSTEM

    This system is controlled by the power management control ECU, and is activated by the throttle position sensor and motor. The power management control ECU controls the following functions: ON-OFF, -/SET, +/RES, CANCEL vehicle speed operation and motor output control.


    • The power management control ECU compares the driving vehicle speed from the skid control ECU assembly with the stored vehicle speed set through the cruise control main switch. The power management control ECU controls the throttle motor of the throttle body to close the valve when the driving speed is less than the stored speed.

    • The power management control ECU receives signals such as ON-OFF, -/SET, +/ RES, and CANCEL from the cruise control main switch.

    • The power management control ECU illuminates the combination meter cruise control indicator light when it receives the cruise control switch on signal.

    • The power management control ECU illuminates the SET indicator light in the combination meter assembly when the cruise control system is operated by pushing the cruise control switch to -/SET.

    • The power management control ECU cancels the cruise control system when the brake pedal is depressed and the power management control ECU receives the stop light switch signal.

    • The ECM cancels control of vehicle speed when the shift lever is moved from D to any other position.

    • The ECM cancels control of vehicle speed when the transmission shift switch assembly is used to select the 3rd, 2nd or 1st range with the shift lever in D.

  2. LIMIT CONTROL


    1. Low speed limit:

      The lowest possible limit of the speed setting range is set at approximately 40 km/h (25 mph). The cruise control system cannot be set when the driving vehicle speed is below the low speed limit. Cruise control operation will be automatically canceled and the set speed is stored in memory when the vehicle speed decreases below the low speed limit 40 km/h (25 mph) while the cruise control is operating.

    2. High speed limit:

      The highest possible limit of the speed setting range is set at approximately 200 km/h (125 mph). The cruise control system cannot be set when the driving vehicle speed is over the high speed limit. Also, +/RES cannot be used to increase speed beyond the high speed limit.

  3. OPERATION OF CRUISE CONTROL

    The cruise control main switch operates 7 functions: SET, COAST, TAP-DOWN, RESUME, ACCELERATION (ACCEL), TAP-UP, and CANCEL. The SET, TAP-DOWN and COAST functions, and the RESUME, TAP-UP and ACCEL functions are operated with the same switch. The cruise control switch is an automatic return type switch which turns on only while operating it in each arrow direction and turns off after releasing it.


    1. SET CONTROL

      Vehicle speed is stored and constant speed control is maintained when pushing the switch to -/SET while driving with the cruise control main switch on (the cruise control indicator light is illuminated), and the vehicle speed is within the set speed range (between the low and high speed limits). Also, the cruise control "SET" indicator light turns on.

    2. COAST CONTROL

      The ECM changes the cruise control demanding throttle opening angle to 0° and decelerates the vehicle when -/SET on the cruise control main switch is pressed and held while the cruise control system is operating. When the cruise control switch is released from -/SET, the vehicle speed is stored and constant speed control is maintained.

      Tech Tips

      The throttle valve is not fully closed due to idle speed control, etc.

    3. TAP-DOWN CONTROL

      When tapping down the cruise control main switch to -/SET (for approximately 0.6 seconds) while the cruise control system is in operation, the stored vehicle speed decreases each time by approximately 1 km/h (or 1.0 mph). When the cruise control switch is released from -/SET and the difference between the driving and stored vehicle speed is more than 5 km/h (3 mph), the vehicle speed is stored and constant speed control is maintained.

    4. ACCEL CONTROL

      The throttle valve motor of the throttle position sensor and motor is instructed by the ECM to open the throttle valve when +/RES on the cruise control main switch is pressed and held while the cruise control system is operating. When the cruise control switch is released from +/RES, the vehicle speed is stored and constant speed is maintained.

    5. TAP-UP CONTROL

      When tapping up the cruise control switch to +/RES (for approximately 0.6 seconds) while the cruise control system is in operation, the stored vehicle speed increases each time by approximately 1 km/h (or 1.0 mph). However, when the difference between the driving and the stored vehicle speed is more than 5 km/h (3 mph), the stored vehicle speed will not be changed.

    6. RESUME CONTROL

      After a control cancellation operation is performed by cancel control which stores the vehicle speed, the set vehicle speed at the time of the control cancellation operation can be resumed by driving the vehicle at a speed between approximately 40 km/h and the high speed limit and turning the +/RES switch on

    7. CANCEL CONTROL


      1. Manual cancel

        Performing any of the following cancels the cruise control system (the stored vehicle speed in the power management control ECU is maintained).


        • Depressing the brake pedal.

        • Pushing the cruise control main switch to CANCEL.

        • Turning the cruise control switch main off (set speed is not stored in memory).

        • Moving the shift lever from D or S to any other position.

        • Selecting the S3, S2, or S1 range with the shift lever in S.

        • Selecting the D3, D2 or D1 range using the transmission shift switch assembly with the shift lever in D.

  4. AUTO CANCEL (FAIL-SAFE)

    This system has an automatic cancellation function Click here.