LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2017 >> RC F >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Drivers Assistance Systems - ADAS >> Cruise Control System - Diagnostics - Introduction >> Cruise Control System >> System Description [09/2014 - 11/2017] >> System Description [09/2014 - 11/2017]

System Description [09/2014 - 11/2017]

  1. CRUISE CONTROL SYSTEM 

    This system is controlled by the ECM, and control is performed using the throttle position sensor and motor. The ECM controls the following functions: ON/OFF, - (COAST)/SET, + (ACCEL)/RES (RESUME), CANCEL, vehicle speed operation and shift down control.

    • The ECM compares the vehicle speed from the speed sensor with the stored vehicle speed set using the cruise control switch. The ECM instructs the throttle valve motor of the throttle body with motor assembly to close the valve when the vehicle speed is greater than the stored vehicle speed, and instructs it to open the valve when the vehicle speed is less than the stored vehicle speed.
    • The ECM receives signals such as ON/OFF, - (COAST)/SET, + (ACCEL)/RES (RESUME), and CANCEL from the cruise control switch and executes the command.
    • The ECM illuminates the combination meter assembly cruise control indicator when the cruise control system is turned on using the cruise control switch (ON/OFF button).
    • The ECM turns off the combination meter assembly cruise control indicator and displays a warning message when a malfunction occurs during cruise control driving.
    • The ECM illuminates the combination meter assembly cruise control SET indicator when control of vehicle speed begins after the cruise control switch is pushed to -/SET while driving.
      GTY370223Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Cruise Control Indicator
      *2 Cruise Control SET Indicator
    • The ECM cancels control of vehicle speed when the brake pedal is depressed and the ECM receives a signal from the stop light switch assembly.
    • 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 shift paddle switch assembly is used to select the 3rd, 2nd or 1st range with the shift lever in D.
    • The ECM cancels control of vehicle speed when the cruise control switch is pulled to CANCEL.
    • The ECM cancels control of vehicle speed when the cruise control system is turned off using the cruise control switch (ON/OFF button).
  2. LIMIT CONTROL 
    1. Low speed limit

      The lowest possible set speed is approximately 40 km/h (25 mph). The cruise control system cannot be set when the vehicle speed is below the low speed limit. Control of vehicle speed will be automatically canceled but the stored vehicle speed will be maintained when the vehicle speed drops below the low speed limit while the cruise control system is controlling vehicle speed.

    2. High speed limit

      The highest possible set speed is approximately 200 km/h (124 mph). The cruise control system cannot be set when the vehicle speed is over the high speed limit. Also, + (ACCEL)/RES (RESUME) cannot be used to increase the speed beyond the high speed limit.

  3. OPERATION OF CRUISE CONTROL 

    The cruise control switch is used to turn the cruise control system on and off, as well as operate 7 functions: SET, - (COAST), TAP-DOWN, RES (RESUME), + (ACCEL), TAP-UP, and CANCEL. The SET, TAP-DOWN, and - (COAST) functions, and the RES (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 being operated in the direction of each arrow, and turns off when it is released.

    1. SET CONTROL

      The vehicle speed is stored and speed control begins when the cruise control switch is pushed to -/SET while driving with the cruise control system on (while the cruise control indicator is illuminated), and the vehicle speed is within the set speed range (between the low and high speed limits).

    2. - (COAST) CONTROL

      When the cruise control system is controlling vehicle speed and the cruise control switch is pushed to -/SET and held in that position, the cruise control system sends a "throttle valve opening angle 0°" demand signal to the ECM. Following this, the vehicle speed is stored and maintained when the cruise control switch is released.

      HINT: 

      An actual throttle valve opening angle of 0° is not possible due to items such as idle speed control.

    3. TAP-DOWN CONTROL

      When the cruise control system is controlling vehicle speed and the cruise control switch is tapped to -/SET (for approximately 0.6 seconds or less), the stored vehicle speed decreases by approximately 1.6 km/h (1 mph) for each time the switch is tapped. When the cruise control switch is tapped to -/SET and the difference between the current and stored vehicle speed is more than approximately 5 km/h (3 mph), the current vehicle speed is stored and speed control is performed.

    4. ACCELERATION CONTROL

      When the cruise control system is controlling vehicle speed and the cruise control switch is pushed to +/RES and held in that position, the cruise control system sends a signal to the ECM to operate the throttle valve motor of the throttle body with motor assembly to open the throttle valve. Following this, the vehicle speed is stored and maintained when the cruise control switch is released.

    5. TAP-UP CONTROL

      When the cruise control system is controlling vehicle speed and the cruise control switch is tapped to +/RES (for approximately 0.6 seconds or less), the stored vehicle speed increases by approximately 1.6 km/h (1 mph) for each time the switch is tapped. When the cruise control switch is tapped to +/RES and the difference between the current and stored vehicle speed is more than approximately 5 km/h (3 mph), the stored vehicle speed will not be changed.

    6. RESUME CONTROL

      If control of vehicle speed by the cruise control system was canceled due to any of the manual cancel conditions (other than turning the cruise control system off using the cruise control switch (ON/OFF button)), and if the vehicle speed is between the low and high speed limits, the stored vehicle speed from the time of cancellation will be resumed and maintained when the cruise control switch is pushed to +/RES.

    7. SHIFT DOWN CONTROL

      When the vehicle is cruising uphill, the transmission may shift down according to AT control. After the ECM judges that uphill cruising has ended based on the throttle valve angle, the transmission will shift up. If the transmission shifts down during acceleration or resume control, it will shift up after acceleration or resume control is completed.

    8. MANUAL CANCEL CONTROL

      Performing any of the following cancels control of vehicle speed by the cruise control system (the stored vehicle speed in the ECM is maintained).

      • Depressing the brake pedal.
      • Moving the shift lever from D to any other position.
      • Selecting the 3rd, 2nd or 1st range using the shift paddle switch assembly with the shift lever in D.
      • Pulling the cruise control switch to CANCEL
      • Turning the cruise control system off using the cruise control switch (ON/OFF button) (the stored vehicle speed in the ECM is not maintained).
  4. AUTO CANCEL (FAIL-SAFE) 

    This system has an automatic cancellation function (fail-safe).

    Refer to FAIL-SAFE CHART [09/2014 - 11/2017] 

scientia non olet · About LEMON Manuals