CAN COMMUNICATION SYSTEM > FAIL-SAFE CHART

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FAIL-SAFE FUNCTION

  1. When communication fails in any of the CAN bus wires (communication wires) 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.

  2. The following chart shows the relationships between components, system functions, and effects of communication failure on these functions. (For further details, see the procedures for each system.)

    Function
    (Function Description)
    		Control Master
    		Related System
    		Fail-safe Operation
    		DTC
    (Driver Detectable)
    ABS control
    (Control driving force while ABS in operation)
    		Skid Control ECU
    		Yaw Rate Sensor
    		Control inoperative
    (gradually stops controlling during ABS control)
    		U0073, U0123, U0124
    (Warning light comes on)
    TRC control
    (Engine power control by VSC/TRC)
    VSC control
    (Controls driving force while VSC in operation)
    		Skid Control ECU
    1. ECM
    2. Steering Sensor
    3. Yaw Rate Sensor
    		TRC control is inoperative
    (TRC control gradually stops)
    VSC control is inoperative
    (VSC control gradually stops)
    		U0073, U0100, U0123, U0124, U0126
    (Warning Light comes on)
    Electric power steering
    (Speed of vehicle induction type torque control)
    		Power Steering ECU
    1. ECM
    2. Skid Control ECU
    3. Engine Stop and Start ECU*4
    		Steering assist force is maintained at the level for about 100 km/h (62 mph).
    		U0100, U0129, U1103
    (Warning Light comes on)
    Air Conditioner Control
    		Air Conditioning Amplifier Assembly
    1. ECM
    2. Power Steering ECU
    3. Combination Meter ECU
    4. Main Body ECU
    5. Engine Stop and Start ECU*4
    		Air conditioning function stops
    		U0100, U0131, U0142, U0155
    (Air conditioning inoperative)
    Event Recorder
    (Tracks event data such as vehicle speed and accelerator opening angle and records data)
    		Center Airbag Sensor Assembly
    1. ECM
    2. Combination Meter ECU
    3. Main Body ECU
    		Data not recorded
    		None
    Meter display (Vehicle status display and indicator light control)
    		Combination Meter ECU
    1. ECM
    2. Skid Control ECU
    3. Power Steering ECU
    4. Center Airbag Sensor Assembly
    5. Power Management Control ECU*1
    6. Power Source Control ECU*2
    7. Main Body ECU
    8. Certification ECU*3
    9. Engine Stop and Start ECU*4
    		Light does not come on, illuminates abnormally, or blinks abnormally
    		U0100, U0129, U0131, U0151
    (Abnormal light illumination)
    Buzzer Control
    		Combination Meter ECU
    1. Skid Control ECU
    2. Air Conditioning Amplifier Assembly
    3. Main Body ECU
    4. Certification ECU*3
    		Buzzer function stops
    		U0129
    (Buzzer does not sound)
    Push Start
    		Power Management Control ECU*1
    Power Source Control ECU*2
    1. ECM
    2. Combination Meter ECU
    3. Main Body ECU
    4. Certification ECU*3
    		The message "Depress brake pedal and push engine switch to start" is not displayed when necessary.
    		U0100, U1133,
    (Same as shown to the left)
    Watch Sub Bus
    (Power Management Bus)
    		Power Management Control ECU*1
    1. ECM
    2. Air Conditioning Amplifier Assembly
    		-
    		U0100, U1002
    (None)
    Key Lock-in Prevention
    		Main Body ECU
    		Combination Meter ECU
    		Key lock-in prevention function inoperative
    		None
    (Control is inoperative)
    Smart/Wireless Control
    		Main Body ECU
    1. Combination Meter ECU
    2. Certification ECU*3
    		Entry lock/unlock not possible
    		U0142, U0155, U0327
    (Control is inoperative)
    Illumination Control
    		Main Body ECU
    1. Combination Meter ECU
    2. Certification ECU*3
    		Illumination control not possible
    		U0142, U0327
    (Dome light will not come on)
    Back Door Open Control
    		Main Body ECU
    1. Combination Meter ECU
    2. Certification ECU*3
    		Power back door open function inoperative
    		U0142, U0155, U0327
    (Control is inoperative)
    Stop and Start System*4
    		Engine Stop and Start ECU
    1. ECM
    2. Skid Control ECU
    3. Power Steering ECU
    4. Center Airbag Sensor Assembly
    5. Combination Meter ECU
    6. Main Body ECU
    7. Air Conditioning Amplifier Assembly
    		Idling stop control stopping
    		U0100, U0121, U0131, U0140, U0151, U0164
    (Warning Light comes on)
    *1: for 1KR-FE and 1NR-FE with Entry and Start System
    *2: for 1ND-TV with Entry and Start System
    *3: w/ Entry and Start System
    *4: w/ Stop and Start System