CAN COMMUNICATION SYSTEM FAIL-SAFE CHART


  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. (For further details, see the pages for each system.)

      Function Control Master System Related Fail-safe Operation Driver Detectable

      DTC Detection

      (ECU that stored DTC)

      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). -

      U0100

      (Air conditioning amplifier assembly)

      Compressor control


      • Judges compressor lock according to engine speed.

      		 Air conditioning amplifier assembly ECM Control is performed based on default engine speed of 0 rpm. -

      U0100

      (Air conditioning amplifier assembly)

      Simple load control


      • Performs electric load control according to load control level signal.

      		 Air conditioning amplifier assembly Power steering ECU with motor assembly Load control is not performed. -

      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)

      Fuel Consumption display


      • Displays graph of fuel consumption per minute and history of total fuel consumption.

      • Navigation ECU sub-assembly

      • Radio and display receiver assembly

      • ECM

      • Brake actuator assembly

      • Combination meter assembly

      When communication with ECM or skid control ECU is interrupted:


      • Display is not updated.

      When communication with combination meter is interrupted:


      • Display is not updated.

      • Numeric part of driveable mileage is cleared.

      		 -

      U0100

      U0129

      U0155

      (Navigation ECU sub-assembly)

      (Radio and display receiver assembly)

      Parking assist monitor control


      • Displays rear view monitor based on steering sensor, vehicle speed and vehicle information.

      		 Navigation ECU sub-assembly

      • Steering sensor

      • Main body ECU (Multiplex network body ECU)

      When communication with steering angle sensor is interrupted:


      • Message is shown indicating that guide lines cannot be displayed.

      		 -

      U0073

      U0126

      U0140

      (Navigation ECU sub-assembly)

      Destination identification


      • Identifies destination based on destination and destination package information, and selects the time zone and language used for the display.

      • Navigation ECU sub-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 ECU sub-assembly)

      (Radio and display receiver assembly)

      Vehicle customization function


      • Allows changing of operation and control conditions for vehicle functions via multi-display operation.

      • Navigation ECU sub-assembly

      • Radio and display receiver assembly

      • Smart key ECU assembly (Certification ECU)

      • Main body ECU (Multiplex network body ECU)

      • 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 main body ECU remote communication permit/prohibit state.

      		 Customizable items are not displayed.

      U0073

      (Navigation ECU sub-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

      • Combination meter assembly

      • 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

      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 control Main body ECU (Multiplex network body ECU)

      • ECM

      • Smart key ECU assembly (Certification ECU)

      • Interior lights turn off.

      • Inside handle light turn off.

      When communication with smart key ECU is interrupted:


      • Interior lights do not turn off right after getting out of the vehicle.

      U0100

      U0327

      (Main body ECU (Multiplex network body ECU))
      Entry function/wireless control Main body ECU (Multiplex network body ECU) Smart key ECU assembly (Certification ECU) Entry lock/unlock control is not possible. -

      U0327

      (Main body ECU (Multiplex network body ECU))

      Parking assist system control


      • Judges shift lever position.

      • Judges vehicle speed.

      		 Clearance warning ECU Assembly

      • ECM

      • TCM

      • Combination meter assembly

      • Main body ECU (Multiplex network body ECU)

      		 Obstacle detection is stopped. -

      When communication with ECM or TCM is interrupted:


      • U0101

        (Clearance warning ECU Assembly)

      When communication with Main body ECU (Multiplex network body ECU) is interrupted:


      • U0142 (Clearance warning ECU Assembly)

      When communication with combination meter is interrupted:


      • U0155

        (Clearance warning ECU Assembly)

      Electric load control


      • Performs idle up according to electric loads.

      		 ECM

      • Power steering ECU with motor assembly

      • Main body ECU (Multiplex network body ECU)

      • Air conditioning amplifier assembly

      		 Idle up according to electric loads is not performed. - -

      Air conditioning cooperative operation


      • Performs idle up according to compressor load.

      • Performs air conditioning cut control.

      		 ECM Air conditioning amplifier assembly

      Air conditioning system does not use cooperative controls.

      (Idle up is not performed.)

      		 Air conditioning system does not operate. -

      Charge control


      • Performs idle up according to charging request.

      		 Smart key ECU assembly (Certification ECU)

      • Main body ECU (Multiplex network body ECU)

      • Air conditioning amplifier assembly

      		 Idle up according to charging request is not performed. Taillights flicker and blower airflow changes. -

      Eco control


      • Adjusts throttle response in consideration of actual fuel economy.

      		 ECM

      • Main body ECU (Multiplex network body ECU)

      • Air conditioning amplifier assembly

      		 Eco mode does not operate. - -

      Coast downshift timing change according to air conditioning load


      • Delays upshifts according to warm-up request.

      • ECM

      • ECT

      		 Air conditioning amplifier assembly Coast downshift does not occur. Coast downshift shock reduction performance deteriorates. -

      Power steering control


      • Calculates assist current according to torque sensor value and vehicle speed and drives motor.

      		 Power steering ECU with motor assembly

      • ECM

      • Brake actuator assembly

      • Steering sensor

      When communication with ECM is interrupted:


      • Power steering assist not provided.

      When communication with skid control ECU is interrupted:


      • Control continues based on a default speed of 100 km/h (62 mph) because vehicle speed is unrecognizable.

        (Steering wheel feels heavy when the vehicle speed is below 100 km/h (62 mph) and feels light at speeds above 100 km/h (62 mph).)

      		 EPS warning light illuminates.

      U0100

      U0129

      (Power steering ECU with motor assembly)

      Steering assist calculation


      • Changes assist force based on vehicle speed.

      		 Power steering ECU with motor assembly Brake actuator assembly

      Control continues based on a default speed of 100 km/h (62 mph) because vehicle speed is unrecognizable.

      (Steering wheel feels heavy when the vehicle speed is below 100 km/h (62 mph) and feels light at speeds above 100 km/h (62 mph).)

      		 EPS warning light illuminates.

      U0129

      (Power steering ECU with motor assembly)
      Steering/steering angle sensor initialization and zero point learning. Power steering ECU with motor assembly Brake actuator assembly Steering initialization and zero point learning are not performed. EPS warning light illuminates.

      U0129

      (Power steering ECU with motor assembly)

      Assist map selection


      • Selects proper assist map according to destination, engine type, etc.

      		 Power steering ECU with motor assembly

      • ECM

      • Brake actuator assembly

      Default map is used to assist because proper assist map cannot be selected.

      (Steering feel may be different.)

      		 EPS warning light illuminates.

      U0100

      U0129

      (Power steering ECU with motor assembly)

      Entry function


      • Entry lock/unlock, entry luggage compartment open.

      • Warning.

      • Performs entry illumination

        (Interior illumination etc).

      • Main body ECU (Multiplex network body ECU)

      • Smart key ECU assembly (Certification ECU)

      • Main body ECU (Multiplex network body ECU)

      • Combination meter assembly

      		 Entry unlock is performed again.

      • Entry lock/unlock or entry luggage compartment open does not operate.

      • Warning functions (Key confinement, Key not in vehicle, Key reminder etc.) do not operate, Key confinement prevention control does not operate.

      • Entry illumination does not operate.

      U0142

      U0155

      (Smart key ECU assembly (Certification ECU))

      Wireless function


      • Locks and unlocks doors, etc. via remote operation.

      		 Main body ECU (Multiplex network body ECU) Smart key ECU assembly (Certification ECU) Wireless lock, unlock and luggage compartment opener do not operate - -

      Engine switch backlighting control


      • Turns on/off engine switch illumination linked with interior lights etc.

      		 Smart key ECU assembly (Certification ECU) Main body ECU (Multiplex network body ECU) Engine switch backlighting does not illuminate according to interior lights operation -

      U0142

      (Smart key ECU assembly (Certification ECU))

      Meter display


      • Displays vehicle condition and controls indicator lights.

      		 Combination meter assembly

      • ECM

      • Brake actuator assembly

      • Airbag sensor assembly

      • Power steering ECU with motor assembly

      • Main body ECU (Multiplex network body ECU)

      		 Lights do not illuminate or lights always illuminate Lights do not illuminate properly or do not illuminate at all.

      U0100

      U0129

      U0131

      U0142

      U0151

      (Combination meter assembly)
      Vehicle speed display Combination meter assembly Brake actuator assembly Vehicle speed display remains at 0 km/h (0 mph). -

      U0129

      (Combination meter assembly)

      Tachometer


      • Displays engine speed.

      		 Combination meter assembly ECM The needle points at 0 rpm. -

      U0100

      (Combination meter assembly)
      Coolant temperature display Combination meter assembly ECM Display is turned off. - -

      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.

      		 Smart key ECU assembly (Certification ECU) ECM - -

      U0100

      (Smart key ECU assembly (Certification ECU))
      ABS/TRC/VSC control Brake actuator assembly

      • ECM

      • Steering sensor

      • Airbag sensor assembly

      		 Control stops Warning lights and indicators illuminate.

      U0073

      U0100

      U0123

      U0126

      (Brake actuator assembly)

      Power tilt and power telescopic steering column control

      (Starts steering wheel auto return or auto away based on a key removal or insertion signal or equivalent).

      		 Multiplex tilt and telescopic ECU Main body ECU (Multiplex network body ECU) - Auto return/away control does not operate.

      U0142

      (Multiplex tilt and telescopic ECU))

      Lighting system


      • Adjusts headlights vertical aiming according to wheel speed and vehicle pitch angle determined using vehicle height sensor.

      • Swings headlights left or right according to wheel speed and turn radius determined using steering angle.

      		 AFS ECU

      • ECM

      • TCM

      • Brake actuator assembly

      • Steering sensor

      • Main body ECU (Multiplex network body ECU)

      		 Control stops AFS indicator blinks.

      U0100

      U0101

      U0126

      U0129

      U0142

      (AFS ECU)