CAN COMMUNICATION SYSTEM(w/ Central Gateway ECU) 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)

      Anti-lock Brake System Control

      • Prevents the wheels from locking during sudden stops.

      Brake actuator assembly

      -

      • During control: When back-up 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.

      U0073

      (Brake actuator assembly)

      Vehicle Stability Control / Traction Control

      • Suppresses vehicle instability, such as sliding sideways when cornering and wheel slippage when accelerating from rest.

      Brake actuator assembly

      • ECM

      • Airbag sensor assembly

      • Steering sensor (spiral cable with sensor sub-assembly)

      • Power steering ECU with motor assembly

      • During control: When back-up 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 warning light illuminates.

      U0073

      U0100

      U0123

      U0126

      (Brake actuator assembly)

      Hill-start Assist Control

      • Maintains the brake hydraulic pressure to the 4 wheels for 2 seconds with the brake pedal released when starting off on an uphill.

      Brake actuator assembly

      • ECM

      • Airbag sensor assembly

      • Steering sensor (spiral cable with sensor sub-assembly)

      Control cannot be performed.

      • Brake warning light illuminates.

      • ABS warning light illuminates.

      • Slip warning light illuminates.

      U0073

      U0100

      U0123

      U0126

      (Brake actuator assembly)

      Eco Drive Hill Hold Control

      • Maintains brake fluid pressure when changing foot position from the brake pedal to accelerator pedal and starting the engine during eco drive hill hold control. Fluid pressure is held for a maximum of 2 seconds, and then released in 1 second.

      Brake actuator assembly

      • ECM

      • Airbag sensor assembly

      • Steering sensor (spiral cable with sensor sub-assembly)

      • Engine stop and start ECU

      • During control: When back-up control (depressurization control) is complete, further control cannot be performed.

      • Not during control: Control cannot be performed.

      • Brake warning light illuminates.

      • ABS warning light illuminates.

      • Slip warning light illuminates.

      U0073

      U0100

      U0123

      U0124

      U0126

      (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 with motor assembly

      Maintains the latest state (load control is not performed when the system is reset).

      -

      U0131

      (Air conditioning amplifier assembly)

      Panel Dimming Control

      • Controls air conditioning system operation state display and air conditioning control panel switch indicator output based on air conditioning control panel switch operation.

      • If automatic circulation control is available, changes the air inlet mode to fresh air or recirculate mode based on information from the smog ventilation sensor.

      Air conditioning amplifier assembly

      Radio and display receiver assembly

      Control is performed based on default A/C switch state of off and emission existence information is maintained.

      -

      -

      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 Eco Mode Control

      • Performs control in Eco mode using B_ECOMI.

      Air conditioning amplifier assembly

      ECM

      Maintains the latest state (Maintained in normal condition after reset).

      -

      -

      Leveling Control

      • Determines the vehicle driving condition based on the speed of the wheels, calculates vehicle pitch angle based on the vehicle height sensor value and adjusts the vertical aiming of headlights.

      Headlight leveling ECU assembly

      • Brake actuator assembly

      • Main body ECU (multiplex network body ECU)

      Leveling control is stopped. (Headlight beam level remains the same as when the malfunction occurred.)

      -

      U0129

      U0142

      (Headlight leveling ECU assembly)

      Destination Identification

      • Checks if the destination information stored in the headlight leveling ECU assembly and the destination information data transmitted in the CAN bus lines are the same.

      Headlight leveling ECU assembly

      ECM

      -

      -

      U0100

      (Headlight leveling ECU assembly)

      Destination Identification

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

      Radio and display receiver assembly

      Main body ECU (multiplex network body ECU)

      Destination is identified based on the latest value (based on the default value if data has never been received) and operation continues.

      Time zone and language selection screen are different from actual destination.

      U0140

      (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)

      • Combination meter assembly

      • ECM

      • Brake actuator 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)

      • ECM

      The dome light is turned off.

      The dome light does not turn off immediately after the doors are opened and closed.

      U0100

      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

      • Brake actuator assembly

      The daytime running light control does not operate.

      -

      U0100

      (Main body ECU (multiplex network body ECU))

      Back Door Opener

      • Back door open control.

      Main body ECU (multiplex network body ECU)

      Combination meter assembly

      The back door open control does not operate.

      -

      U0155

      (Main body ECU (multiplex network body ECU))

      Display Dimming Control

      Clearance warning ECU assembly

      Main body ECU (multiplex network body ECU)

      • When communication is interrupted while the ignition switch is turned to ON, control is performed based on default value (dimming).

      • When communication is interrupted while the ignition switch is ON, control is performed based on the latest information.

      -

      U0142

      (Clearance warning ECU assembly)

      Shift Position Judgment

      • Receives a shift position signal and uses it as a clearance sonar detection operation condition (for AT vehicles).

      Clearance warning ECU assembly

      ECM

      Operation continues at the default shift position of P.

      -

      U0101

      (Clearance warning ECU assembly)

      Vehicle Speed Judgment

      • Receives a vehicle speed signal and uses it as a clearance sonar detection operation condition.

      Clearance warning ECU assembly

      Combination meter assembly

      Operation continues at the default vehicle speed of 20 km/h (12 mph) or more.

      -

      U0129

      (Clearance warning ECU assembly)

      Distance Correction

      • Corrects distance measured using the ultra sonic sensors based on outside temperature signal.

      Clearance warning ECU assembly

      Air conditioning amplifier assembly

      • Operation continues at the default outside temperature of 25°C (77°F).

      • Simple intelligent parking assist system operation is canceled.

      Simple intelligent parking assist system operation is canceled (indicator is displayed on the combination meter assembly and the buzzer sounds).

      U0164

      (Clearance warning ECU assembly)

      Parking Brake Judgment

      • Receives a parking brake signal and uses it as a clearance sonar detection operation condition.

        (for MT vehicles)

      Clearance warning ECU assembly

      Main body ECU (multiplex network body ECU)

      When communication is interrupted, the system judges the parking brake is ON.

      -

      U0142

      (Clearance warning ECU assembly)

      Engine Status Check

      • Checks engine status and uses it to judge if the simple intelligent parking assist system can be used.

      Clearance warning ECU assembly

      • Engine stop and start ECU

      • ECM

      (w/ Stop and start system)

      • When communication is interrupted while the ignition switch is turned to ON, the simple intelligent parking assist system cannot be operated.

      • When communication is interrupted while the ignition switch is ON, operation is performed based on the latest value.

      When the latest value is zero or communication is interrupted just after the ignition switch is turned to ON, simple intelligent parking assist system operation is canceled (indicator is displayed on the combination meter assembly and the buzzer sounds).

      -

      ECM

      (w/o Stop and start system)

      When communication is interrupted, simple intelligent parking assist system operation is canceled.

      Simple intelligent parking assist system operation is canceled (indicator is displayed on the combination meter assembly and the buzzer sounds).

      U0100

      (Clearance warning ECU assembly)

      Brake Status Judgment

      • Checks brake status and uses it to judge if the simple intelligent parking assist system can be used.

      Clearance warning ECU assembly

      Brake actuator assembly

      When communication is interrupted, simple intelligent parking assist system operation is canceled.

      -

      U0129

      (Clearance warning ECU assembly)

      Vehicle Information Judgment

      • Judges whether the vehicle is AT or MT, RHD or LHD and equipped with the stop and start system, and changes control.

      Clearance warning ECU assembly

      • ECM

      • Main body ECU (multiplex network body ECU)

      • When AT/MT cannot be judged, operation is performed based on the latest value. When communication is interrupted while the ignition switch is turned to ON, the simple intelligent parking assist system cannot be operated.

      • When RHD/LHD cannot be judged, the simple intelligent parking assist system cannot be operated.

      • Availability of the stop and start system cannot be judged.

      • Clearance sonar cannot be operated.

      • Simple intelligent parking assist system operation is canceled (indicator is displayed on the combination meter assembly and the buzzer sounds).

      U0100

      U0142

      (Clearance warning ECU assembly)

      Steering Wheel Control

      • Checks the status of the steering sensor (spiral cable with sensor sub-assembly) and power steering ECU with motor assembly and judges start/cancel of simple intelligent parking assist control. Also checks steering sensor (spiral cable with sensor sub-assembly) status and sends the steering angle signal to the power steering ECU with motor assembly.

      Clearance warning ECU assembly

      Power steering ECU with motor assembly

      Simple intelligent parking assist system operation is canceled.

      Simple intelligent parking assist system operation is canceled (indicator is displayed on the combination meter assembly and the buzzer sounds).

      U0126

      U0131

      (Clearance warning ECU assembly)

      Side Turn Signal Check

      • Checks side turn signal status and decides detection direction.

      Clearance warning ECU assembly

      Combination meter assembly

      Simple intelligent parking assist system operation is canceled.

      -

      -

      Stop and Start System

      • Stops the engine when the vehicle is stationary.

      Engine stop and start ECU

      • Air conditioning amplifier assembly

      • Brake actuator assembly

      • ECM

      • Power steering ECU with motor assembly

      • Main body ECU (multiplex network body ECU)

      • Airbag sensor assembly

      • Combination meter assembly

      • Clearance warning ECU assembly

      • Steering sensor (spiral cable with sensor sub-assembly)

      • When driving in eco drive mode, the engine starts.

      • When not driving in eco drive mode, eco drive cannot be performed.

      Stop and start cancel indicator light blinks.

      U0100

      U0121

      U0126

      U0131

      U0140

      U0151

      U0155

      U0164

      U1110

      (Engine stop and start ECU)

      Engine Related Indicator Display

      • Estimates engine oil deterioration and displays a message, etc., indicating replacement of the oil on the combination meter assembly.

      ECM

      Combination meter assembly

      Engine oil maintenance related items displayed on the combination meter assembly cannot be cleared.

      • Replacement warning is not displayed.

      • The message on the combination meter assembly remains displayed.

      -

      Electrical Load Control

      • Perform idle up according to electric load.

      ECM

      • Air conditioning amplifier assembly

      • Power steering ECU with motor assembly

      • Main body ECU (multiplex network body ECU)

      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

      • Main body ECU (multiplex network body ECU)

      • 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.

      -

      Neutral Control

      • Reduces engine load and performs idle up.

      ECM

      • Brake actuator assembly

      • Airbag sensor assembly

      Neutral control is not performed.

      -

      U0129

      (ECM)

      Stop and Start Control

      • Starts and stops the engine using the stop and start control.

      ECM

      Engine stop and start ECU

      Stop and start control is not performed.

      Stop and start control does not operate.

      U1103

      (ECM)

      Eco Control

      (for Gasoline engine)

      • Adjusts throttle response in consideration of actual fuel economy.

      ECM

      • Air conditioning amplifier assembly

      • Main body ECU (multiplex network body ECU)

      • Combination meter assembly

      Eco mode does not operate.

      • Indicator does not illuminate.

      • Eco mode does not operate.

      -

      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 with motor assembly

      • ECM

      • Brake actuator assembly

      • Steering sensor (spiral cable with sensor sub-assembly)

      • Airbag sensor assembly

      • Power steering does not operate.

      • The steering feel becomes worse (compensation control using the steering angle is stopped).

      • Assist force restricted.

      • Zero point learning is not performed.

      EPS warning light illuminates.

      U0100

      U0129

      (Power steering ECU with motor assembly)

      Assist Map Selection

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

      Power steering ECU with motor assembly

      • Brake actuator assembly

      • ECM

      • Main body ECU (multiplex network body ECU)

      • A temporary map is used to perform assist as an assist map cannot be selected according to vehicle specifications.

      • Steering feel may be unusual.

      • The frame used to select the assist map may change depending on the vehicle.

      EPS warning light illuminates.

      C1581

      (Power steering ECU with motor assembly)

      Entry Function

      • Entry lock/unlock

      • Performs entry illumination (interior illumination etc.).

      • Main body ECU (multiplex network body ECU)

      • Certification ECU (smart key ECU assembly)

      • Main body ECU (multiplex network body ECU)

      • Certification ECU (smart key ECU assembly)

      • ECM

      • Combination meter assembly

      Entry unlock is performed again.

      • Entry lock/unlock or entry back 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.

      • Answer-back continues (maximum of 3 sets) when the doors are unlocked. (Only when the main body ECU (multiplex network body ECU) can receive a request signal from the certification ECU (smart key ECU assembly)).

      • Wrong entry warning is output.

      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))

      Vehicle Speed Display

      • Displays the vehicle speed on the speedometer according to the vehicle speed signal from brake actuator assembly.

      Combination meter assembly

      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 with motor assembly

      Control is performed based on signal value of "Active".

      EPS warning light illuminates.

      U0131

      (Combination meter assembly)

      Slip Warning

      • Slip warning light control.

      Combination meter assembly

      Brake actuator assembly

      Control is performed based on signal value of "Active".

      Slip warning 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.

      -

      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)

      • Main body ECU (multiplex network body ECU)

      • ECM

      • Brake actuator assembly

      • Combination meter assembly

      • Engine stop and start ECU

      After the ignition switch operation, it always takes 1.2 seconds before power source mode changes to off.

      • A message urging engine start operation is not displayed when required.

      • Engine switch indicator blinks in amber.

      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))

      Pre-crash Safety System

      • When the system determines that there is a high possibility of colliding with an obstacle in front of the vehicle, the system activates warnings and performs brake control.

      Pre-crash safety city sensor

      • ECM

      • Airbag sensor assembly

      • Steering sensor (spiral cable with sensor sub-assembly)

      • Brake actuator assembly

      • Combination meter assembly

      Pre-crash safety system operation is canceled.

      • Meter buzzer sounds.

      • PCS OFF warning light flashes.

      • Displays messages on the multi-information display.

      • Master warning light illuminates.

      U0100

      U0123

      U0126

      U0129

      U023A

      (Pre-crash safety city sensor)

      Lane Departure Alert System

      • Warns when vehicle is deviating from its lane.

      Pre-crash safety city sensor

      • ECM

      • Airbag sensor assembly

      • Steering sensor (spiral cable with sensor sub-assembly)

      • Brake actuator assembly

      • Combination meter assembly

      Lane departure and buzzer warning are canceled.

      • Buzzer sounds.

      • Displays messages on the multi-information display.

      • Lane departure alert indicator light does not illuminate.

      U0100

      U0123

      U0126

      U0129

      U0155

      (Pre-crash safety city sensor)

      Road Sign Assist Function

      • Identifies road signs while driving and displays them on the multi-information display.

      Pre-crash safety city sensor

      • ECM

      • Airbag sensor assembly

      • Brake actuator assembly

      Road sign assist function is canceled.

      Displays messages on the multi-information display.

      U0100

      U0123

      U0129

      (Pre-crash safety city sensor)