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 Power management control ECU Control is performed based on default coolant temperature of 80°C (176°F). -

      U0293

      (Air conditioning amplifier assembly)

      Simple Load Control


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

      		 Air conditioning amplifier assembly Power steering ECU 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)

      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 Eco Mode Control


      • Performs control in Eco mode using B_ECOMI.

      		 Air conditioning amplifier assembly Power management control ECU Maintains the latest state. (Maintained in normal condition after reset.) -

      U0293

      (Air conditioning amplifier assembly)

      Fuel Consumption Display


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

      • Navigation receiver assembly*1

      • Navigation ECU sub-assembly*2

      • Radio and display receiver assembly*3

      • Brake booster with master cylinder assembly (Skid control ECU)

      • Combination meter assembly

      • ECM

      • Power management control ECU

      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.

      		 - -

      HV Energy Flow Display


      • Creates energy flow screen which indicates regeneration status and drive force transmission status.

      • Navigation receiver assembly*1

      • Navigation ECU sub-assembly*2

      • Radio and display receiver assembly*3

      		 Power management control ECU If communication stops while the energy flow screen is displayed, the energy flow display disappears and the latest value is maintained for the SOC (state of charge) level display. -

      U0293

      (Navigation receiver assembly*1)

      (Navigation ECU sub-assembly*2)

      (Radio and display receiver assembly*3)

      Parking Assist Monitor Control


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

      		 Navigation ECU sub-assembly*2

      • 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*2)

      Vehicle Customization Function


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

      • Navigation receiver assembly*1

      • Navigation ECU sub-assembly*2

      • Radio and display receiver assembly*3

      • Main body ECU (Multiplex network body ECU)

      • Smart key ECU assembly (Certification ECU)

      • Air conditioning amplifier assembly

      		 When an application that uses phase 4 remote communication is activated (customization/remote diagnosis), the process will be performed regardless of main body ECU (multiplex network body ECU) remote communication permit/prohibit state. -

      U0140

      (Navigation receiver assembly*1)

      (Navigation ECU sub-assembly*2)

      (Radio and display receiver assembly*3)

      Door Lock


      • Controls key linked and automatic door lock/unlock function, key confinement prevention function, etc.

      		 Main body ECU (Multiplex network body ECU)

      • Combination meter assembly

      • ECM

      • Power management control ECU

      • 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

      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))

      Luggage Compartment Door Opener/Luggage Compartment Door Open Control


      • Accepts luggage compartment door opener request.

      		 Main body ECU (Multiplex network body ECU)

      • Combination meter assembly

      • ECM

      • Power management control ECU

      		 Luggage compartment door does not open. -

      U0100

      U0101

      U0155

      (Main body ECU (Multiplex network body ECU))
      Illumination Control Main body ECU (Multiplex network body ECU)

      • Smart key ECU assembly (Certification ECU)

      • Power management control 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.

      U0293

      U0327

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

      U0327

      (Main body ECU (Multiplex network body ECU))

      Drive Torque Control


      • Controls the engine, MG1 and MG2 based on engine information received.

      		 Power management control ECU ECM Vehicle drives using only the motor. Displays messages on the multi-information display.

      U0100

      (Power management control ECU (Hybrid control system))

      Regenerative Operation


      • Provides maximum amount of regeneration based on cooperative control with the ECB system.

      		 Power management control ECU Brake booster with master cylinder assembly (Skid control ECU) Regeneration is prohibited. Displays messages on the multi-information display.

      U0129

      (Power management control ECU (Hybrid control system))

      High Voltage Shut off Control When the Vehicle is Damaged


      • Receives the SRS collision detection signal (CDT-HV) and shuts off the system main relays.

      		 Power management control ECU Airbag sensor assembly Normal driving. Displays messages on the multi-information display.

      U0151

      (Power management control ECU (Hybrid control system))

      HV System Power Processing


      • Determines that an IG2 malfunction cannot be judged when a power supply ECU communication error occurs.

      		 Power management control ECU (Hybrid control system) Power management control ECU (Power management control CPU) Normal driving. Displays messages on the multi-information display.

      U1107

      (Power management control ECU (Hybrid control system))

      Air Conditioning Control


      • Sends a signal from the air conditioning amplifier assembly to the power management control ECU (HV CPU) and from the power management control ECU (HV CPU) to the inverter for the air conditioning system.

      		 Air conditioning amplifier assembly Power management control ECU Air conditioning cooling operation is stopped. -

      U0164

      (Power management control ECU)

      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.

      		 Power management control ECU (Power management control CPU)

      • Main body ECU (Multiplex network body ECU)

      • Combination meter assembly

      • Power management control ECU (Hybrid control system)

      		 None -

      U0140

      U0155

      U0293

      (Power management control ECU (Power management control CPU))

      Cruise Control


      • Calculates demand drive force to maintain vehicle speed.

      		 Power management control ECU Brake booster with master cylinder assembly (Skid control ECU) Cruise control is canceled.

      • Displays messages on the multi-information display.

      • Master warning light illuminates.

      U0122

      (Power management control ECU)

      PTC Heater


      • When there is a heat demand signal that requires operation of the PTC heater (including heating from coolant), idle up is performed.

      		 Air conditioning amplifier assembly ECM

      • Engine idle speed changes.

      • Heating performance deteriorates.

      • PTC heater does not operate.

      		 - -

      Charge Control


      • Performs idle up according to charging request.

      		 Power management control ECU Air conditioning amplifier assembly Idle up according to charging request is not performed. Taillights flicker and blower airflow changes. -

      Power Steering Control


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

      		 Power steering ECU assembly

      • Power management control ECU

      • Brake booster with master cylinder assembly (Skid control ECU)

      • Control is performed based on default assist current for a vehicle speed of 140 km/h (87 mph).

      • Drivability degrades (compensation control using steering angle is stopped).

      		 EPS warning light illuminates.

      U0129

      U0293

      (Power steering ECU assembly)

      Steering Assist Calculation


      • Changes assist force based on vehicle speed.

      		 Power steering ECU assembly

      • Power management control ECU

      • Brake booster with master cylinder assembly (Skid control ECU)

      When communication with skid control ECU is interrupted:


      • Control continues based on a default speed of 140 km/h (87 mph) because vehicle speed is unrecognizable.

      		 EPS warning light illuminates.

      U0129

      U0293

      (Power steering ECU assembly)

      Assist Map Selection


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

      		 Power steering ECU assembly

      • ECM

      • Brake booster with master cylinder assembly (Skid control ECU)

      		 Default map is used to assist because proper assist map cannot be selected. (Steering feel may be different.) EPS warning light illuminates. -

      Steering Assist Compensation Control


      • Provides steering assist with compensation amount based on vehicle speed.

      		 Power steering ECU assembly Brake booster with master cylinder assembly (Skid control ECU) Control is performed based on a default vehicle speed of approximately 140 km/h (87 mph). EPS warning light illuminates.

      U0129

      (Power steering ECU 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.

      U0327

      (Main body ECU (Multiplex network body ECU))

      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. -

      U0142

      (Smart key ECU assembly (Certification ECU))

      Power Switch Backlighting Control


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

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

      U0142

      (Smart key ECU assembly (Certification ECU))
      Vehicle Speed Display Combination meter assembly Brake booster with master cylinder assembly (Skid control ECU) Speedometer is controlled based on a default vehicle speed of 0 km/h (0 mph).

      • The needle points at 0 km/h (0 mph).

      • Drive monitor calculation is stopped.

      U0129

      (Combination meter assembly)

      Airbag

      (Airbag Warning Light Control)

      		 Combination meter assembly Airbag sensor assembly None Airbag warning light illuminates.

      U0151

      (Combination meter assembly)

      EPS Warning

      (EPS Warning Light Control)

      		 Combination meter assembly Power steering ECU assembly None EPS warning light illuminates.

      U0131

      (Combination meter assembly)

      SLIP Warning

      (SLIP Warning Light Control)

      		 Combination meter assembly Brake booster with master cylinder assembly (Skid control ECU) None SLIP indicator illuminates. -
      ABS/TRAC/VSC Control Brake booster with master cylinder assembly (Skid control ECU) Airbag sensor assembly

      • When control is being performed: When back-up control (vehicle behavior stabilization) is complete, braking returns to normal operation and further control is prohibited.

      • When control is not being performed: Control will not be started.

      • Brake warning light (red) illuminates.

      • ABS warning light illuminates.

      • SLIP indicator illuminates.

      • Brake warning light (yellow) illuminates.

      U0073

      U0123

      U0124

      U0126

      U0293

      (Brake booster with master cylinder assembly (Skid control ECU))

      HAC2 Control


      • Maintains brake pressure for 2 seconds when the brake pedal has been depressed further after stopping the vehicle.

      		 Brake booster with master cylinder assembly (Skid control ECU)

      • Power management control ECU

      • Steering sensor

      • Airbag sensor assembly

      • When control is being performed: Once control (depressurization control) has completed, further hill-start assist control is prohibited.

      • When control is not being performed: Hill-start assist control does not start.

      • Brake warning light (red) illuminates.

      • ABS warning light illuminates.

      • SLIP indicator illuminates.

      • Brake warning light (yellow) illuminates.

      U0073

      U0123

      U0124

      U0126

      U0293

      (Brake booster with master cylinder assembly (Skid control ECU))

      Hybrid Regenerative Operation


      • Regenerative cooperative control with the HV system.

      		 Brake booster with master cylinder assembly (Skid control ECU) Power management control ECU

      • When control is being performed: HV cooperative control is continued based on the latest value and gradually decreased. After this, HV cooperative control is prohibited.

      • When control is not being performed: HV cooperative control does not start.

      • Brake warning light (red) illuminates.

      • ABS warning light illuminates.

      • SLIP indicator illuminates.

      • Brake warning light (yellow) illuminates.

      U0073

      U0293

      (Brake booster with master cylinder assembly (Skid control ECU))

      Blind Spot Monitor Control


      • Detects vehicles in blind spot of adjacent lane and informs driver.

      		 Blind spot monitor sensor RH

      • Steering sensor

      • Brake booster with master cylinder assembly (Skid control ECU)

      • Main body ECU (Multiplex network body ECU)

      • Power management control ECU

      		 Control stops. Displays messages on the multi-information display.

      U0126

      U0129

      U0142

      U0232

      U0293

      (Blind spot monitor sensor RH)

      Gateway System (Between V Bus and Sub Bus 11)


      • Relays data between V bus and sub bus 11, and monitors ECUs connected to sub bus 11.

      		 Power management control ECU Blind spot monitor sensor RH - -

      U0233

      U1002

      (Power management control ECU (Gateway system))

      Tech Tips


      • *1: for Navigation receiver type

      • *2: for Radio and display type (w/ Intuitive parking assist system)

      • *3: for Radio and display type (w/o Intuitive parking assist system)