CAN COMMUNICATION SYSTEM (for LHD) > FAIL-SAFE CHART

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FAIL-SAFE FUNCTION

  1. When communication fails in any of the CAN bus lines (communication lines) due to a short circuit or other causes, the fail-safe function, which is specified for each system, operates to prevent the system from malfunctioning.

    Function
    		HV Control ECU (HV)
    		HV Control ECU (ENGINE)
    		Skid Control ECU
    		Steering Control ECU
    		Yaw Rate Sensor
    		Action when communication is disabled
    		DTC detection (if the driver can recognize a malfunction)
    Toyota Hybrid System-II (THS-II) Control
    (to optimize the combination between the engine and motor drive power for driving)
    		●
    		○
    		-
    		-
    		-
    		Safe running
    		Recognizable. (HV caution light and MIL come on.)
    Regenerative Braking (the motor acts as a generator that depends on wheel rotation and generates electricity to be stored in the HV battery)
    		○
    		-
    		●
    		-
    		-
    		Regenerative braking will stop.
    		Recognizable. (VSC, ABS, ECB, and 4WD warning lights come on.)
    VSC Control (to control the braking force when the VSC is activated)
    		○
    		-
    		●
    		○
    		○
    		VSC function will stop.
    		Recognizable. (VSC, ABS, ECB, and 4WD warning lights come on)
    Electric Power Steering (to calculate the assist current from the torque sensor value and vehicle speed, and output the current to the motor)
    		○
    		-
    		○
    		○
    		-
    		When communication with the THS-II is disabled:
    Assist will stop.
    When communication with the ECB is disabled:
    Control will continue using assist force that is equivalent to the vehicle speed of 100 km/h (62mile/h).
    		Recognizable.
    (EPS warning light blinks.)
    Parking Assist Monitor (to display the direction of movement when reversing)
    		○
    		-
    		○
    		○
    		-
    		When communication with the steering sensor is disabled:
    Parking assist monitor only is operative. (Guide function will stop.)
    When communication with the THS-ll is disabled:
    Parking assist monitor will be inoperative.
    		Recognizable with the guide function inoperative and the screen not displaying the parking assist monitor.
    Multi-Information Display (to display operating condition, shift position, and DTC)
    		○
    		○
    		○
    		-
    		-
    		Light does not come on, or remains on.
    		Recognizable (Tire air pressure, BRAKE, ABS, P/S lights come on.)
    Shift position light goes off

    HINT:
    1. ● : Control master
    2. ○ : System related


    Function
    		Power Steering ECU
    		Distance Control ECU
    		Television Camera ECU
    		Network Gateway ECU
    		Action when communication is disabled
    		DTC detection (if the driver can recognize a malfunction)
    Toyota Hybrid System-II (THS-II) Control
    (to optimize the combination between the engine and motor drive power for driving)
    		-
    		-
    		-
    		-
    		Safe running
    		Recognizable. (HV caution light and MIL come on.)
    Regenerative Braking (the motor acts as a generator that depends on wheel rotation and generates electricity to be stored in the HV battery)
    		-
    		-
    		-
    		-
    		Regenerative braking will stop.
    		Recognizable. (VSC, ABS, ECB, and 4WD warning lights come on.)
    VSC Control (to control the braking force when the VSC is activated)
    		-
    		-
    		-
    		-
    		VSC function will stop.
    		Recognizable. (VSC, ABS, ECB, and 4WD warning lights come on.)
    Electric Power Steering (to calculate the assist current from the torque sensor value and vehicle speed, and output the current to the motor)
    		●
    		-
    		-
    		-
    		When communication with the THS-II is disabled:
    Assist will stop.
    When communication with the ECB is disabled:
    Control will continue using assist force that is equivalent to the vehicle speed of 100 km/h ( 62mph).
    		Recognizable.
    (EPS warning light blinks.)
    Parking Assist Monitor (to display the direction of movement when reversing)
    		-
    		-
    		●
    		-
    		When communication with the steering sensor is disabled:
    Parking assist monitor only is operative. (Guide function will stop.)
    When communication with the THS-ll is disabled:
    Parking assist monitor will be inoperative.
    		Recognizable with the guide function inoperative and the screen not displaying the parking assist monitor.
    Multi-Information Display (to display operating condition, shift position, and DTC)
    		○
    		-
    		-
    		●
    Meter
    		Light does not come on, or remains on.
    		Recognizable (Tire air pressure, BRAKE, ABS, P/S lights come on.)
    Shift position light goes off

    HINT:
    1. ● : Control master
    2. ○ : System related