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Fail-Safe Chart [08/2016 - ]

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  1. FAIL-SAFE FUNCTION 
    1. When communication fails in any of the CAN bus lines (communication lines), a fail-safe function(s) will operate. The fail-safe function that is specified for each system operates to prevent those systems from malfunctioning.
    2. The following table shows the effects on each system when communication is impossible.
      Function Control Master System Related Fail-safe Operation Driver Detectable DTC Detection
      (ECU that stored DTC)
      Anti-lock Brake System Control
      • Prevents the wheels from locking during sudden stops.
      		 Skid control ECU (brake actuator assembly) Airbag sensor assembly
      • During control:

        When backup control (stabilizing the vehicle) is complete, the system changes to normal braking and prohibits control.

      • Not during control:

        Control cannot be performed.
      • Brake warning light illuminates.
      • ABS warning light illuminates.
      • Slip indicator light illuminates.
      		 U0073
      U0124
      (Skid control ECU (brake actuator assembly))
      Vehicle Stability Control / Traction Control
      • Suppresses vehicle instability, such as sliding sideways when cornering and wheel slippage when accelerating from rest.
      		 Skid control ECU (brake actuator assembly)
      • ECM
      • Airbag sensor assembly
      • Steering sensor
      • During control:

        When backup control (stabilizing the vehicle) is complete, the system changes to normal braking and prohibits control.

      • Not during control:

        Control cannot be performed.
      • Brake warning light illuminates.
      • ABS warning light illuminates.
      • Slip indicator light illuminates.
      		 U0073
      U0100
      U0124
      U0126
      (Skid control ECU (brake actuator assembly))
      Air Conditioning Control
      • Corrects engine speed, such as for idle up.
      • Controls outlet air temperature, outlet mode change and airflow volume based on engine coolant temperature signal.
      • Corrects engine coolant temperature map and changes compressor lock judgment value.
      		 Air conditioning amplifier assembly ECM
      • Control is performed based on default coolant temperature of 80°C (176°F).
      • Control is performed based on engine model (differs between vehicle models).
      		 - U0100
      (Air conditioning amplifier assembly)
      Compressor Control
      • Determines whether the compressor is locked using engine speed information.
      		 Air conditioning amplifier assembly ECM Control is performed based on default engine speed of 0 rpm. - U0100
      (Air conditioning amplifier assembly)
      Simple Load Control
      • Limits electrical load control according to the load control level.
      		 Air conditioning amplifier assembly Power steering ECU assembly Maintains the latest state (load control is not performed when the system is reset). - U0131
      (Air conditioning amplifier assembly)
      Panel Dimming Control
      • Outputs dimmer signal to LIN connected panels according to display dimmer signal.
      		 Air conditioning amplifier assembly Main body ECU (multiplex network body ECU) Dimming mode and non-dimming mode cannot be switched. - U0142
      (Air conditioning amplifier assembly)
      Destination Identification Control
      • Changes air conditioning control pattern according to destination.
      		 Air conditioning amplifier assembly Main body ECU (multiplex network body ECU) Maintains the latest state. - U0142
      (Air conditioning amplifier assembly)
      Ambient Temperature Correction Control
      • Switches air conditioning system operation condition and corrects value of displayed ambient temperature according to vehicle speed signal.
      		 Air conditioning amplifier assembly Combination meter assembly Control is performed based on default vehicle speed of 0 km/h (0 mph).
      • Correction level for displayed ambient temperature declines.
      • Correction level for outlet airflow declines.
      		 U0155
      (Air conditioning amplifier assembly)
      Air Conditioning Control
      • Displays the set temperature, air outlet selection, etc.
      • Navigation receiver assembly
      • Radio and display receiver assembly
      		 Air conditioning amplifier assembly
      • Air conditioning system indicators turn off.
      • If set temperature is shown on multi-information display or multi-display, set temperature display turns off.
      		 Displays messages on the multi-information display. U0073
      U0164
      (Navigation receiver assembly)
      (Radio and display receiver assembly)
      Fuel Consumption Display
      • Displays graph of fuel consumption per minute and history of total fuel consumption.
      • Navigation receiver assembly
      • Radio and display receiver assembly
      • ECM
      • Skid control ECU (brake actuator assembly)
      		 Display is not updated. - U0100
      U0129
      (Navigation receiver assembly)
      (Radio and display receiver assembly)
      Rear View Monitor System
      • Displays images from the rear view camera.
      • Navigation receiver assembly
      • Radio and display receiver assembly
      • ECM
      • Main body ECU (multiplex network body ECU)
      		 None Screen does not change to the camera screen. U0100
      (Navigation receiver assembly)
      (Radio and display receiver assembly)
      Destination Identification
      • Identifies destination based on destination and destination package information, and selects the time zone and language used for the display.
      • Navigation receiver assembly
      • Radio and display receiver assembly
      		 Main body ECU (multiplex network body ECU) Destination is identified based on information received before communication is interrupted. Time zone and language selection screen are different from actual destination. U0140
      (Navigation receiver assembly)
      (Radio and display receiver assembly)
      Vehicle Customization Function
      • Allows changing of operation and control conditions for vehicle functions via multi-display operation.
      • Navigation receiver assembly
      • Radio and display receiver assembly
      • Main body ECU (multiplex network body ECU)
      • Air conditioning amplifier assembly
      • Certification ECU (smart key ECU assembly)
      • Customization via multi-display is not possible, but customization via main body ECU is possible.
      • When an application that uses remote communication is activated (customization/remote diagnosis), the process will be performed regardless of meter ECU remote communication permit/prohibit state.
      		 Related customization items are not displayed or do not change to set values. U0073
      (Navigation receiver assembly)
      (Radio and display receiver assembly)
      Door Lock
      • Controls key linked and automatic door lock/unlock function, key confinement prevention function, etc.
      		 Main body ECU (multiplex network body ECU)
      • ECM
      • Airbag sensor assembly
      • Combination meter assembly
      • When the ignition switch is ON, control is performed based on the latest information.
      • When the ignition switch is off, key linked operation is permitted.
      • Speed sensitive automatic lock control does not occur.
      • Shift linked automatic lock control does not occur.
      • Shift linked automatic unlock control does not occur.
      • Automatic lock/unlock cannot be changed.
      		 - U0100
      U0101
      U0151
      U0155
      (Main body ECU (multiplex network body ECU))
      Display Automatic Dimming
      • Display dimming control.
      		 Main body ECU (multiplex network body ECU) Combination meter assembly Automatic dimming control for displays does not operate when taillights are turned on. - U0155
      (Main body ECU (multiplex network body ECU))
      Illumination
      • Performs illumination control.
      		 Main body ECU (multiplex network body ECU) Certification ECU (smart key ECU assembly) The dome light is turned off. The dome light does not turn off immediately after the doors are opened and closed. U0327
      (Main body ECU (multiplex network body ECU))
      Entry Function/Wireless Control Certification ECU (smart key ECU assembly) Main body ECU (multiplex network body ECU) Entry lock/unlock control is not possible. - U0327
      (Main body ECU (multiplex network body ECU))
      Light Control
      • Daytime running light control.
      		 Main body ECU (multiplex network body ECU) ECM The daytime running light control does not operate. - U0100
      (Main body ECU (multiplex network body ECU))
      Electrical Load Control
      • Performs idle up according to electric load.
      		 ECM Power steering ECU assembly Idle up according to the electrical load is not performed. Engine idle speed changes. -
      Air Conditioning Cooperative Operation
      • Performs idle up according to compressor load.
      		 ECM Air conditioning amplifier assembly Air conditioning system does not use cooperative controls. Air conditioning system does not operate. -
      PTC Heater
      • Performs idle up when there is a heat demand signal that requires operation of the PTC heater.
      		 ECM Air conditioning amplifier assembly PTC heater does not operate.
      • Engine idle speed changes.
      • Heating performance deteriorates.
      • PTC heater does not operate.
      		 -
      Charge Control
      • Performs idle up according to charging request.
      		 ECM Air conditioning amplifier assembly
      • Idle up according to charging request is not performed.
      • Charging control is not prohibited.
      • Idle up according to charging request is not performed.
      • Tail lights flicker and blower airflow changes.
      		 -
      Eco Driving Indicator
      • Displays information to the driver to encourage eco-driving.
      		 ECM Combination meter assembly - No information is displayed. -
      Eco Control
      • Adjusts throttle response in consideration of actual fuel economy.
      		 ECM Air conditioning amplifier assembly Eco mode does not operate.
      • Indicator does not illuminate.
      • Eco mode does not operate.
      		 -
      Neutral Control
      • Reduces engine load and performs idle up.
      		 ECM
      • Skid control ECU (brake actuator assembly)
      • Airbag sensor assembly
      		 Neutral control is not performed. - -
      Electronic Power Steering System
      • Calculates the current to be used for the steering assist according to the torque sensor value and vehicle speed, and then operates the motor.
      		 Power steering ECU assembly
      • ECM
      • Skid control ECU (brake actuator assembly)
      • Steering sensor
      • Airbag sensor assembly
      • Power steering does not operate.
      • Assist force restricted.
      • The steering feel becomes worse (compensation control using the steering angle is stopped).
      • Zero point learning is not performed.
      		 EPS warning light illuminates. U0100
      U0129
      (Power steering ECU assembly)
      Assist Map Selection
      • Selects proper assist map according to destination, engine type, etc.
      		 Power steering ECU assembly
      • ECM
      • Skid control ECU (brake actuator assembly)
      • Main body ECU (multiplex network body ECU)
      • Default map is used to assist because proper assist map cannot be selected.
      • Steering feel may be different.
      		 EPS warning light illuminates. C1581
      (Power steering ECU assembly)
      LKA System
      • Calculates current to be used for steering assist according to commanded values from driving support ECU assembly and forward recognition camera, and then operates motor.
      • Power steering ECU assembly
      • Driving support ECU assembly
      • Skid control ECU (brake actuator assembly)
      • Steering sensor
      • Forward recognition camera
      		 LKA control is stopped. - U023A
      (Power steering ECU assembly)
      Entry Function
      • Entry lock/unlock.
      • Performs entry illumination (interior illumination etc.).
      • Warning.
      • Main body ECU (multiplex network body ECU)
      • Certification ECU (smart key ECU assembly)
      • ECM
      • Combination meter assembly
      • Main body ECU (multiplex network body ECU)
      		 Entry unlock is performed again.
      • Entry lock/unlock or entry luggage door unlatch does not operate.
      • Warning functions (key confinement, key not in vehicle, key reminder, etc.) do not operate and key confinement prevention control does not operate.
      • Entry illumination does not operate.
      		 U0100
      U0142
      U0155
      (Certification ECU (smart key ECU assembly))
      Wireless Function
      • Locks and unlocks doors etc. via remote operation.
      		 Main body ECU (multiplex network body ECU)
      • Main body ECU (multiplex network body ECU)
      • Certification ECU (smart key ECU assembly)
      		 - Wireless lock and unlock do not operate. -
      Engine Switch Illumination Control
      • Operates the engine switch illumination in conjunction with the dome light illumination, etc.
      		 Certification ECU (smart key ECU assembly)
      • Main body ECU (multiplex network body ECU)
      • Certification ECU (smart key ECU assembly)
      • Combination meter assembly
      • If the engine switch is not illuminated, it does not illuminate.
      • When the engine switch is illuminated due to the dome light, the illumination does not turn off.
      • When the DC cut fuse is disconnected and the engine switch illuminated due to the dome light, the illumination does not turn off.
      • If the engine switch is not illuminated, it does not illuminate.
      • When the engine switch is illuminated due to the dome light, the illumination does not turn off.
      • When the DC cut fuse is disconnected and the engine switch illuminated due to the dome light, the illumination does not turn off.
      		 U0142
      (Certification ECU (smart key ECU assembly))
      Engine Start/Stop Switch (Power Source Mode Change)
      • Using start/stop switch signal as trigger, changes power source mode automatically and requests starter operation when conditions are met.
      		 Certification ECU (smart key ECU assembly) ECM - A message urging engine start operation is not displayed when required. U0100
      (Certification ECU (smart key ECU assembly))
      Engine Start Control
      • Allows the engine to start by pressing the engine switch once.

        (Cranking hold)

      		 Certification ECU (smart key ECU assembly) ECM Cranking is stopped when engine starting is judged based on an engine speed signal received via direct line. - U0100
      (Certification ECU (smart key ECU assembly))
      Vehicle Speed Display
      • Displays the vehicle speed on the speedometer according to the vehicle speed signal from skid control ECU (brake actuator assembly).
      		 Combination meter assembly Skid control ECU (brake actuator assembly) Control is performed based on signal value of 0.
      • The needle points at 0 km/h (0 mph).
      • Drive monitor calculation is stopped.
      		 U0129
      (Combination meter assembly)
      Tachometer
      • Displays information on the tachometer.
      		 Combination meter assembly ECM Control is performed based on signal value of 0.
      • The tachometer displays 0 rpm.
      • The drive monitor stops calculating.
      		 U0100
      (Combination meter assembly)
      Airbag Warning
      • Airbag warning light control.
      		 Combination meter assembly Airbag sensor assembly Control is performed based on signal value of "Active". Airbag warning light illuminates. U0151
      (Combination meter assembly)
      EPS Warning
      • EPS warning light control.
      		 Combination meter assembly Power steering ECU assembly Control is performed based on signal value of "Active". EPS warning light illuminates. U0131
      (Combination meter assembly)
      Slip Warning
      • Slip indicator light control.
      		 Combination meter assembly Skid control ECU (brake actuator assembly) Control is performed based on signal value of "Active". Slip indicator light illuminates. -
      Engine Coolant Temperature Receiver Gauge Control Combination meter assembly ECM Control is performed based on signal value of 0.
      • Needle of engine coolant temperature receiver gauge is at the middle or below.*1
      • Engine coolant temperature gauge bar segments are not displayed.*2
      		 -
      Tire Pressure Warning
      • Tire pressure warning light control.
      		 Combination meter assembly Main body ECU (multiplex network body ECU) Control is performed based on signal value of "Active". Tire pressure warning light illuminates. U0142
      (Combination meter assembly)
      LKA/LDA/SWS System
      (Recognizes the lane markers of the lane the vehicle is in using the forward recognition camera and performs the following operations based on the vehicle condition and information captured by the forward recognition camera.)
      • If the system judges that the vehicle may deviate from the lane it is in, the system performs steering assist to help the driver correct the path of the vehicle.
      • If the system judges that the vehicle deviated from the lane it is in, the system sounds a buzzer to inform the driver of lane departure.
      • If the system judges unsteady driving, the system informs the driver to stop and take a rest.
      		 Forward recognition camera
      • ECM
      • Airbag sensor assembly
      • Steering sensor
      • Skid control ECU (brake actuator assembly)
      • Power steering ECU assembly
      • Main body ECU (multiplex network body ECU)
      • Combination meter assembly
      • Millimeter wave radar sensor assembly
      • Driving support ECU assembly
      • Control stops.
      • EPS torque request suspended.
      • Displays thin lane markers on the multi-information display.
      • Displays messages on the multi-information display.
      		 U0100
      U0101
      U0123
      U0126
      U0129
      U0131
      U0142
      U0155
      U0235
      U023A
      U1104
      (Forward recognition camera)
      Automatic High Beam
      • Controls the high beam automatically when the forward recognition camera detects a preceding vehicle or an oncoming vehicle.
      		 Forward recognition camera
      • ECM
      • Skid control ECU (brake actuator assembly)
      • Millimeter wave radar sensor assembly
      • Airbag sensor assembly
      • Main body ECU (multiplex network body ECU)
      		 Performs control based on the signals received before the malfunction occurred. Displays messages on the multi-information display. U0100
      U0123
      U0129
      U0142
      U0235
      (Forward recognition camera)
      PCS
      • Detects pedestrian and other vehicles and applies the brakes automatically if necessary.
      		 Forward recognition camera
      • ECM
      • Airbag sensor assembly
      • Skid control ECU (brake actuator assembly)
      • Main body ECU (multiplex network body ECU)
      • Millimeter wave radar sensor assembly
      • Driving support ECU assembly
      		 Detection processing is reset and signals indicating that the forward recognition camera is not detecting objects are sent to the driving support ECU assembly.
      • PCS indicator light flashes.
      • Displays messages on the multi-information display.
      		 U0100
      U0123
      U0129
      U0142
      U0235
      U1104
      (Forward recognition camera)
      PCS
      • Performs pre-collision alarm control, pre-collision brake assist control and pre-collision brake control when an obstruction is detected.
      		 Driving support ECU assembly
      • ECM
      • Airbag sensor assembly
      • Steering sensor
      • Skid control ECU (brake actuator assembly)
      • Millimeter wave radar sensor assembly
      • Forward recognition camera
      • Driving support ECU assembly
      		 Control stops.
      • PCS indicator light flashes.
      • Displays messages on the multi-information display.
      		 U0100
      U0125
      U0126
      U0129
      U0235
      U023A
      U1104
      (Driving support ECU assembly)
      • *1: except Multi-information Display (Segment LCD Type)
      • *2: for Multi-information Display (Segment LCD Type)
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