CAN COMMUNICATION SYSTEM(w/ Toyota Safety Sense) 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)

      Communication interruption detection


      • Monitors NS and NM frames of ECUs connected to global bus to detect when communication with ECU interrupted.

      		 Central gateway ECU (network gateway ECU) ECUs connected to global bus Time when communication was interrupted is recorded. - -

      Meter display request


      • Indicator and multi-display output display request to meter

      		 Combination meter assembly ECM - Coolant temperature, fuel efficiency, etc. are not displayed correctly. -

      Electric fan


      • Electric fan control according to A/C request

      		 ECM Air conditioning amplifier assembly Electric fan operates in fail-safe mode - -

      Electric water pump


      • Electric water pump control according to A/C request

      		 ECM Air conditioning amplifier assembly Electric water pump operates in fail-safe mode - -

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

      U0293

      (Air conditioning amplifier assembly)

      Panel dimming control


      • Outputs dimming information to LIN panel based on display dimming information

      		 Air conditioning amplifier assembly Main body ECU (Multiplex network body ECU) Maintains the previous state (After reset, set to dim). Cannot change between dim / not dim (After reset, fixed to dim mode).

      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.

      		 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

      (Radio and display receiver assembly)

      Fuel consumption display


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

      		 Radio and display receiver assembly

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

      • ECM

      • Combination meter assembly

      • Hybrid vehicle control ECU

      • Update of the per-minute fuel consumption display (per minute fuel consumption calculation) on the navigation Eco screen (per-minute fuel consumption screen) is stopped.

      • When drivable mileage is displayed on the navigation Eco screen, the displayed drivable mileage turns off due to data communication stop.

      		 -

      U0100

      U0129

      U0155

      U0293

      (Radio and display receiver assembly)

      HV energy flow display


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

      		 Radio and display receiver assembly

      • Hybrid vehicle control ECU

      • ECM

      		 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. -

      U0100

      U0293

      (Radio and display receiver assembly)

      Destination identification


      • Identifies destination bases 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 information received before communication is interrupted. Time zone and language selection screen are different from actual destination.

      U0140

      (Radio and display receiver assembly)

      Vehicle Customization Function


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

      		 Radio and display receiver assembly

      • Main body ECU (Multiplex network body ECU)

      • Air conditioning amplifier assembly

      • Smart key ECU assembly (Certification 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 meter ECU remote communication permit/prohibit state.

      		 Related customization items are not displayed or do not change to set values.

      U0073

      (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

      • Hybrid vehicle control ECU

      • Airbag sensor assembly

      • While the ignition switch is ON (IG), performs operations using the last information before the communication stop.

      • While the ignition switch off, the 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 Control


      • Turns on the interior lights when the smart key is brought near the vehicle.

      		 Main body ECU (Multiplex network body ECU) Smart key ECU assembly (Certification ECU) Interior lights turn off. -

      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))

      Light Control


      • Daytime running light control

      		 Main body ECU (Multiplex network body ECU)

      • ECM

      • Hybrid vehicle control ECU

      		 Daytime running light control is not possible. -

      U0100

      U0293

      (Main body ECU (Multiplex network body ECU))

      Tire Pressure Warning


      • Turns on/off the tire pressure warning light.

      		 Main body ECU (Multiplex network body ECU) Combination meter assembly - -

      U0155

      (Main body ECU (Multiplex network body ECU))

      Automatic high beam


      • Automatically suppresses high beam output when pre-crash safety city sensor detects an oncoming vehicle or a vehicle in the lane ahead.

      Main Body ECU

      (Multiplex Network Body ECU)

      		 Pre-crash safety city sensor Automatic high beam is not possible (automatic high beam warning light blinks). Automatic high beam indicator light flashes.

      U023A

      (Main Body ECU (Multiplex Network Body ECU))

      Drive Torque Control


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

      		 Hybrid vehicle control ECU ECM Vehicle drives using only the motor. MIL illuminates.

      U0100

      (Hybrid vehicle control ECU)

      Regenerative Operation


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

      		 Hybrid vehicle control ECU Brake booster with master cylinder assembly (Skid control ECU) Regeneration is prohibited. MIL illuminates.

      U0129

      (Hybrid vehicle control ECU)

      High Voltage Shut Off Control when the vehicle is damaged


      • Receives the SRS collision detection signal and shuts off the system main relays.

      		 Hybrid vehicle control ECU Airbag sensor assembly Normal driving.

      • Hybrid system warning light illuminates.

      • Displays messages on the multi-information display.

      U0151

      (Hybrid vehicle control ECU)

      HV System Power Processing (w/ Power switch)


      • Monitors whether IG2 is stuck ON based on IG2 information from the smart key ECU assembly (certification ECU).

      		 Hybrid vehicle control ECU Smart key ECU assembly (Certification ECU) Ignition switch turns off 10 seconds after the vehicle is stopped and shift lever is moved to P.

      • Hybrid system warning light illuminates.

      • Displays messages on the multi-information display.

      U1107

      (Hybrid vehicle control ECU)

      HV system power processing (w/o Power switch)


      • Monitors whether IG2 is stuck ON based on IG1 information from the main body ECU (multiplex network body ECU).

      		 Hybrid vehicle control ECU Main body ECU (Multiplex network body ECU) Ignition switch turns off 10 seconds after the vehicle is stopped and shift lever is moved to P.

      • Hybrid system warning light illuminates.

      • Displays messages on the multi-information display.

      U0140

      (Hybrid vehicle control ECU)

      Air conditioning control


      • Sends a signal from the air conditioning amplifier assembly to the hybrid vehicle control ECU to the inverter for the air conditioning system.

      		 Hybrid vehicle control ECU Air conditioning amplifier assembly Normal driving. -

      U0164

      (Hybrid vehicle 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

      		 Smart key ECU assembly (Certification ECU)

      • Main body ECU (Multiplex network body ECU)

      • Combination meter assembly

      • Hybrid vehicle control ECU

      		 None -

      U0140

      U0155

      U0293

      (Smart key ECU assembly (Certification ECU))

      Cruise control


      • Calculates demand drive force to maintain vehicle speed

      		 Hybrid vehicle control ECU Brake booster with master cylinder assembly (Skid control ECU) Cruise control is canceled.

      • Hybrid system warning light illuminates.

      • Displays messages on the multi-information display.

      U0122

      (Hybrid vehicle control ECU)

      Charge control


      • Performs idle up according to charging request

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

      Electronic power steering system


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

      		 Power steering ECU assembly

      • Hybrid vehicle control ECU

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

      • Airbag sensor assembly

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

      • Electronic power steering does not operate.

      • Steering assistance is temporarily restricted.

      • Zero point learning is not performed.

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

      		 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 -

      • 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 assembly)

      Entry function


      • Entry lock/unlock

      • 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 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 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)
      HV indicator display Combination meter assembly Hybrid vehicle control ECU

      • HV indicator turns off

      • HV indicator display out of range.

      		 -

      U0100

      (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.

      U0129

      (Combination meter assembly)

      HV drive guide display


      • Displays EV conditions

      		 Combination meter assembly ECM EV condition display turns off -

      U0100

      (Combination meter assembly)

      Automatic high beam indicator

      (Automatic high beam indicator light control)

      		 Combination meter assembly Main body ECU (Multiplex network body ECU) Keep the last signal state until ignition switch off. - -

      PCS warning

      (PCS warning light control)

      		 Combination meter assembly Pre-crash safety city sensor PCS warning light flashes. PCS warning light flashes.

      U023A

      (Combination meter assembly)

      PCS

      (PCS light control)

      		 Combination meter assembly Pre-crash safety city sensor Keep the last signal state until ignition switch off. -

      U023A

      (Combination meter assembly)

      PCS option judgment

      (Decide PCC ECU existence based on PCS existence flag)

      		 Combination meter assembly Pre-crash safety city sensor Keep the last signal state until ignition switch off. -

      U023A

      (Combination meter assembly)

      PCS sensitivity display

      (Display PCS sensitivity based on PCS sensitivity displaying request signal)

      		 Combination meter assembly Pre-crash safety city sensor Keep the last signal state until ignition switch off. -

      U023A

      (Combination meter assembly)

      Pre-crash safety warning buzzer

      (Pre-crash safety warning buzzer control)

      		 Combination meter assembly Pre-crash safety city sensor Keep the last signal state until ignition switch off. -

      U023A

      (Combination meter assembly)

      LDA option judgment

      (Decide PCC ECU existence based on LDA existence flag)

      		 Combination meter assembly Pre-crash safety city sensor Keep the last signal state until ignition switch off. -

      U023A

      (Combination meter assembly)

      Go to service warning

      (Go to service warning light control)

      		 Combination meter assembly Hybrid vehicle control ECU Keep the last signal state until ignition switch off. - -

      Lane departure alert warning buzzer

      (Lane departure alert warning buzzer control)

      		 Combination meter assembly Pre-crash safety city sensor Lane departure alert warning buzzer are canceled. Lane departure alert warning buzzer not sound.

      U023A

      (Combination meter assembly)
      ABS control Brake booster with master cylinder assembly (Skid control ECU)

      • Hybrid vehicle control ECU

      • Airbag sensor assembly

      • During control: After ending backup control (stabilizing the vehicle), the system changes to normal braking and prohibits control.

      • Not during control: Control cannot start.

      • Brake warning light (red) illuminates.

      • ABS warning light illuminates.

      • SLIP indicator illuminates.

      • Brake warning light (yellow) illuminates.

      U0073

      U0123

      U0124

      (Brake booster with master cylinder assembly (Skid control ECU))
      VSC/TRC control Brake booster with master cylinder assembly (Skid control ECU)

      • Hybrid vehicle control ECU

      • Airbag sensor assembly

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

      • During control: After ending backup control (stabilizing the vehicle), the system changes to normal braking and prohibits control.

      • Not during control: Control cannot 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))

      Hill-start assist control 3


      • 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)

      • Hybrid vehicle control ECU

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

      • Airbag sensor assembly

      • During control: After ending backup control (pressure reduction control), the system changes to normal braking and prohibits control, or control continues, and after normal control finishes, prohibits control.

      • Not during control: Control cannot 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)

      • Hybrid vehicle control ECU

      • Airbag sensor assembly

      • 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

      U0123

      U0124

      U0293

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

      Pre-crash safety system


      • Warns and applies automatic braking when the collision is imminent with an obstacle in front of the vehicle.

      		 Pre-crash safety city sensor

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

      • Airbag sensor assembly

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

      • Hybrid vehicle control ECU

      • Combination meter assembly

      		 Control stops.

      • Pre-crash safety warning buzzer sound.

      • PCS warning light flashes.

      • Displays messages on the multi-information display.

      • Master warning light illuminates.

      U0123

      U0126

      U0129

      U023A

      U0293

      (Pre-crash safety city sensor)

      Lane departure alert system


      • Warns when vehicle is deviating from its lane.

      		 Pre-crash safety city sensor

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

      • Hybrid vehicle control ECU

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

      • Airbag sensor assembly

      • Combination meter assembly

      		 Lane departure alert warning buzzer are canceled.

      • Pre-crash safety warning buzzer sound.

      • Displays messages on the multi-information display.

      • LDA indicator light illuminates (yellow).

      U0123

      U0126

      U0129

      U0155

      U0293

      (Pre-crash safety city sensor)