CAN COMMUNICATION SYSTEM(w/ Toyota Safety Sense) FAIL-SAFE CHART


  1. FAIL-SAFE FUNCTION


    1. When communication fails in any of the main wires (communication lines) due to a short circuit or other causes, the fail-safe function, which is specified for each system, operates to prevent the system from malfunctioning.

    2. The table below shows the effects on each system when communication is impossible. For further details, refer to each system.

      System

      Function

      (Function Description)

      		 Control Master System Related Fail-safe Operation

      DTC

      (Driver Detectable)
      Central Gateway ECU Communication interruption detection Central gateway ECU (network gateway ECU) ECUs connected to global bus Time when communication was interrupted is recorded.

      Nothing

      (Nothing)
      Engine Engine control system indication ECM (for 1ND-TV) Combination meter assembly Meter indication cannot be cleared.

      Nothing

      (Meter indication cannot be cleared.)
      Engine Electrical load control ECM (for 2NR-FKE) Power steering ECU assembly The idle speed increase for an electrical load is not performed.

      Nothing

      (The idle speed changes.)
      Engine Electrical load control ECM (for 1KR-FE) Power steering ECU assembly Change in fuel cut cancellation rpm in response to request from power steering ECU is not performed.

      Nothing

      (Nothing)
      Engine Air conditioner-linked control ECM Air conditioning amplifier assembly Air conditioner-linked control does not operate. (cannot idle up)

      Nothing

      (Air conditioning inoperative.)
      Engine PTC heater ECM (for 2NR-FKE and 1ND-TV) Air conditioning amplifier assembly PTC heater does not operate. (does not permit operations)

      Nothing

      (The idle speed changes. The heater function worsens. PTC heater does not operate.)
      Engine Charging control ECM (for 2NR-FKE and 1ND-TV) Air conditioning amplifier assembly, Main body ECU (multiplex network body ECU), Certification ECU (smart key ECU assembly) The idle speed increase for a charge request is not performed.

      Nothing

      (The idle speed increase for a charge request is not performed.)
      Charge control is not prohibited.

      Nothing

      (Tail lights flicker and blower airflow changes.)
      Engine Charging control ECM (for 1KR-FE) Air conditioning amplifier assembly, Main body ECU (multiplex network body ECU) Nothing

      Nothing

      (Nothing)
      Engine Eco driving indicator ECM (for 2NR-FKE) Combination meter assembly Indicator is turned off.

      Nothing

      (Detected by the status that the indicator is turned off.)
      Engine Integrated control ECM (for 2NR-FKE and 1ND-TV) Skid control ECU (brake actuator assembly), Power steering ECU assembly Following performances are not operative: Stable constant-speed drivability, starting ability, re-acceleration ability and improved feeling of acceleration by estimating the required torque from the driver's accelerator pedal control and performing torque control according to the driving situation.

      Nothing

      (Following performances are not operative: Stable constant-speed drivability, starting ability, re-acceleration ability and improved feeling of acceleration by estimating the required torque from the driver's accelerator pedal control and performing torque control according to the driving situation.)
      Engine Integrated control ECM (for 1KR-FE) Skid control ECU (brake actuator assembly) Torque request from skid control ECU (brake actuator assembly) is not accepted.

      Nothing

      (Nothing)
      Engine Eco Control ECM (for 2NR-FKE) Air conditioning amplifier assembly, Combination meter assembly, Engine stop and start ECU Eco mode does not operate.

      U1103

      (Detected by failure of Eco mode operation.)
      Engine ECT system indicators ECM (for 2NR-FKE) Combination meter assembly Cannot shift to the power or snow mode driving control.

      Nothing

      (Indicator light does not come on.)
      Engine Neutral Control ECM (for 2NR-FKE) Skid control ECU (brake actuator assembly) Neutral control does not operate.

      U0129

      (Nothing)
      Engine Cruise control (w/ Cruise Control System) ECM (for 2NR-FKE and 1ND-TV) Skid control ECU (brake actuator assembly), Combination meter assembly Nothing

      Nothing

      (Indicator light blink.)
      Engine Pre-crash safety system ECM Lane recognition camera sensor During pre-crash operation, the accelerator opening angle does not fully close.

      Nothing

      (Pre-crash safety system does not operate.)
      Airbag Event Recorder Center airbag sensor assembly ECM, Skid control ECU (brake actuator assembly An invalid value is stored

      Nothing

      (Nothing)
      VSC ABS control Skid control ECU (brake actuator assembly) (w/ VSC) Center 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.

      U0073, U0124

      (Brake warning light comes on. ABS warning light comes on. Slip indicator light comes on.)
      VSC VSC control Skid control ECU (brake actuator assembly) (w/ VSC) ECM, Steering angle sensor (spiral cable sub-assembly), Center 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.

      U0073, U0100, U0124, U0126

      (Brake warning light comes on. ABS warning light comes on. Slip indicator light comes on.)
      VSC Hill-start assist control 3 Skid control ECU (brake actuator assembly) (w/ VSC) ECM, Steering angle sensor (spiral cable sub-assembly), Center 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.

      U0073, U0100, U0124, U0126

      (Brake warning light comes on. ABS warning light comes on. Slip indicator light comes on.)
      ABS ABS control Skid control ECU (brake actuator assembly) (w/o VSC) Center 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.

      U0073, U0124

      (Brake warning light comes on. ABS warning light comes on. Slip indicator light comes on.)
      Air Conditioning Air conditioning control Air Conditioning Amplifier Assembly ECM

      • Coolant signal during the ignition switch ON: Controlled with default value of 80°C.

      • Engine model during the ignition switch ON: Controlled with default value which differs according to vehicle models.

      • Not controlled without the ignition switch ON.

      U0100

      (Nothing)
      Air Conditioning Compressor control Air Conditioning Amplifier Assembly ECM

      • Control is performed based on default engine speed of 0 rpm.

      • Not controlled without the ignition switch ON.

      U0100

      (Nothing)
      Air Conditioning Simple load control Air Conditioning Amplifier Assembly Power steering ECU assembly

      • Previous status held during the ignition switch ON. (when resetting: no load control.)

      • Not controlled without the ignition switch ON.

      U0131

      (Nothing)
      Air Conditioning Panel dimming control Air Conditioning Amplifier Assembly Main body ECU (multiplex network body ECU)

      • Previous status held during the ignition switch ON. (when resetting: no load control.)

      • Not controlled without the ignition switch ON.

      U0142

      (Cannot switch between dimming and not dimming (after resetting, dimming status remains), Not IG-ON: Nothing.)
      Air Conditioning Destination determinate control Air Conditioning Amplifier Assembly Main body ECU (multiplex network body ECU)

      • Previous status held during the ignition switch ON.

      • Not controlled without the ignition switch ON.

      U0142

      (Nothing)
      Air Conditioning External temperature compensation control Air Conditioning Amplifier Assembly Combination meter assembly

      • Speed signal input during the ignition switch ON : Controlled with the default value of 0 km/h.

      • Not controlled without the ignition switch ON.

      U0155

      (The matching reliability of the displayed external temperature to the actual external temperature is deteriorated. The suitability level of air conditioner outlet airflow compensation is reduced.)
      Radio and Display Air Conditioning Control Radio and display receiver assembly Air conditioning amplifier assembly

      • Air conditioning system indicators turn off.

      • If set temperature is shown on combination meter assembly, set temperature display turns off.

      • Air conditioning function(s) are prohibited.

      U0073, U0164

      (Displays messages on the multi-information display.)
      Radio and Display Fuel Consumption Display Radio and display receiver assembly ECM, Skid control ECU (brake actuator assembly), Combination meter assembly

      • Updating of average per minute fuel consumption is stopped. (The graph of average per minute fuel consumption history displayed to that point is not deleted.)

      • Updating of current aggregated fuel consumption is stopped.

      • When the cruising range is displayed, the numerical part of the cruising range is deleted due to a communication interruption.

      U0100, U0129, U0155

      (The graph of average per minute fuel consumption is not updated. Most recent value in the graph of average per minute fuel consumption is deleted. In the graph of average per minute fuel consumption, the numerical part of the cruising range is deleted.)
      Radio and Display Vehicle Customization Function Radio and display receiver assembly Main body ECU (multiplex network body ECU), Air conditioning amplifier assembly, Combination meter 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.

      Nothing

      (Related customization items are not displayed or do not change to set values.)
      Radio and Display Time Stamp Function Main body ECU (multiplex network body ECU) Main body ECU (multiplex network body ECU) Nothing

      U0073, U0140

      (Nothing)
      Radio and Display Rear View Monitor System Radio and display receiver assembly ECM Nothing

      U0100

      (Screen does not change to the camera screen.)
      Main body Alarm Main body ECU (multiplex network body ECU) Certification ECU (smart key ECU assembly) Nothing

      U0120, U0327

      (Nothing)
      Main body Automatic Dimming of Display Main body ECU (multiplex network body ECU) Combination meter assembly

      • Conduct the display auto dimming control without the tail cancel status.

      • If the light sensor illumination signal value is less than the display dimming value, the in-room displays and indicators are dimmed.

      U0155

      (Nothing)
      Main body Illumination Main body ECU (multiplex network body ECU) ECM, Certification ECU (smart key ECU assembly)

      • The dome light is turned off.

      • The interior foot light illumination is turned off.

      U0100, U0101, U0120, U0327

      (The dome light is not turned off immediately after the vehicle is left.)
      Main body Entry and start/Wireless Main body ECU (multiplex network body ECU) Certification ECU (smart key ECU assembly) Entry and start/wireless control does not operate.

      U0120, U0327

      (Detected by failure of entry lock/unlock operation.)
      Main body Lighting control (DRL control) Main body ECU (multiplex network body ECU) ECM DRL control operation fails.

      Nothing

      (Detected by failure of DRL control.)
      Main body Automatic high beam Main body ECU (multiplex network body ECU) Pre-crash safety city sensor Automatic high beam is not possible (Automatic high beam warning light blinks).

      U023A

      (Automatic high beam indicator light flashes.)
      EPS Electronic power steering system Power steering ECU assembly ECM, Steering angle sensor (spiral cable sub-assembly), Center airbag sensor assembly, Skid control ECU (brake actuator assembly)

      • 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).

      U0100, U0129

      (EPS indicator light comes on.)
      EPS DTC output Combination meter assembly ECM, Power steering ECU assembly Nothing

      Nothing

      (Nothing)
      EPS Assist map selection Power steering ECU assembly Main body ECU (multiplex network body ECU), ECM, Skid control ECU (brake actuator assembly)

      • An assist mapping corresponding to the vehicle cannot be selected, so assist is performed using a preliminary map.

      • The vehicle's steering may feel abnormal.

      • The frame used for assist map selection may change from vehicle to vehicle.

      C1581

      (EPS indicator light comes on.)
      EPS Warning light illumination Combination meter assembly Power steering ECU assembly Nothing

      Nothing

      (Nothing)
      EPS ECE79 Power steering ECU assembly - Nothing

      Nothing

      (Nothing)
      Certification ECU Entry function Certification ECU (smart key ECU assembly), Main body ECU (multiplex network body ECU) Main body ECU (multiplex network body ECU), Combination meter assembly, Engine stop and start ECU, ECM

      • Perform retrying entry unlock.

      • The previous value is maintained.

      U0100, U0142, U0155, U1103

      (The entry lock, entry unlock or entry back door unlatch do not operate. The entry alarm (key lock-in, passenger has brought key out of vehicle, key reminder, etc.) does not operate or key lock-in prevention control does not operate. The entry illumination does not operate. The answer back function continuously operates when an unlock operation is performed. Falsely outputs the smart warning.)
      Certification ECU Wireless Function Certification ECU (smart key ECU assembly) Certification ECU (smart key ECU assembly), Main body ECU (multiplex network body ECU) Nothing

      Nothing

      (Wireless lock and unlock do not operate.)
      Certification ECU Engine Switch Illumination Control Certification ECU (smart key ECU assembly) Main body ECU (multiplex network body ECU), Certification ECU (smart key ECU assembly), Combination meter assembly

      • When the engine switch is illuminated due to the dome light, the illumination does not turn off.

      • When the D.C.C-cut fuse is disconnected and the engine switch illuminated due to the dome light, the illumination does not turn off.

      • The previous value is maintained.

      U0142

      (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 D.C.C-cut fuse is disconnected and the engine switch illuminated due to the dome light, the illumination does not turn off.)
      Certification ECU Engine Start/Stop Switch (Power Source Mode Change) Certification ECU (smart key ECU assembly) Main body ECU (multiplex network body ECU), ECM, Combination meter assembly Nothing

      U0100, U0140, U0155

      (A message urging engine start operation is not displayed when required. )
      Certification ECU Engine Start Control 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

      (Nothing)
      Engine Stop and Start ECU Stop and start system Engine stop and start ECU ECM (for 2NR-FKE and 1KR-FE), Center airbag sensor assembly, Skid control ECU (brake actuator assembly), Air conditioning amplifier assembly, Main body ECU (multiplex network body ECU), Power steering ECU assembly, Combination meter assembly, Center airbag sensor assembly, Steering angle sensor (Spiral cable sub-assembly)

      • Under operation: Restarting.

      • Not under operation: the stop and start operation prohibited.

      U0100, U0121, U0131, U0140, U0151, U0155, U0164

      (Light blinks. Displays messages on the multi-information display.)
      Combination meter

      Vehicle speed indication

      (speedometer display for vehicle speed signal from skid control ECU (brake actuator assembly))

      		 Combination meter assembly Skid control ECU (brake actuator assembly) Signal is treated as 0.

      U0129

      (Vehicle speed on the meter is indicated as 0 km/h. Drive monitor calculation stops.)
      Combination meter Tachometer Combination meter assembly ECM Signal is treated as 0.

      U0100

      (Tachometer rpm displayed as 0 rpm. Drive monitor calculation stops.)
      Combination meter

      Airbag

      (Airbag warning ON/OFF)

      		 Combination meter assembly Center airbag sensor assembly Signal is treated as active.

      U0151

      (Warning light comes on.)
      Combination meter EPS warning Combination meter assembly Power steering ECU assembly Signal is treated as active.

      U0131

      (Warning light comes on.)
      Combination meter Slip warning Combination meter assembly Skid control ECU (brake actuator assembly) Signal is treated as active.

      Nothing

      (Indicator light comes on.)
      Combination meter Automatic high beam indicator Combination meter assembly Main body ECU (Multiplex network body ECU) Keep the last signal state until ignition switch off.

      Nothing

      (Nothing)
      Combination meter PCS warning Combination meter assembly Pre-crash safety city sensor PCS warning light flashes.

      U023A

      (PCS warning light flashes.)
      Combination meter PCS warning Combination meter assembly Pre-crash safety city sensor Keep the last signal state until ignition switch off.

      U023A

      (Nothing)
      Combination meter PCS option judgment Combination meter assembly Pre-crash safety city sensor Keep the last signal state until ignition switch off.

      U023A

      (Nothing)
      Combination meter PCS sensitivity display Combination meter assembly Pre-crash safety city sensor Keep the last signal state until ignition switch off.

      U023A

      (Nothing)
      Combination meter Pre-crash safety warning buzzer Combination meter assembly Pre-crash safety city sensor Keep the last signal state until ignition switch off.

      U023A

      (Nothing)
      Combination meter LDA option judgment Combination meter assembly Pre-crash safety city sensor Keep the last signal state until ignition switch off.

      U023A

      (Nothing)
      Combination meter Lane departure alert warning buzzer Combination meter assembly Pre-crash safety city sensor Lane departure alert warning buzzer are canceled.

      U023A

      (Lane departure alert warning buzzer not sound.)
      Pre-crash safety city sensor Pre-crash safety system Pre-crash safety city sensor Skid control ECU (brake actuator assembly), center airbag sensor assembly, steering angle sensor (spiral cable sub-assembly), ECM and combination meter assembly Control stops.

      U0100, U0123, U0126 and U0129

      (Pre-crash safety warning buzzer sound. PCS warning light flashes. Displays messages on the multi-information display. Master warning light come on.)
      Pre-crash safety city sensor Lane departure alert system Pre-crash safety city sensor Skid control ECU (brake actuator assembly), ECM, steering angle sensor (spiral cable sub-assembly), center airbag sensor assembly, and combination meter assembly Control stops.

      U0100, U0123, U0126, U0129 and U0155

      (Pre-crash safety warning buzzer sound. LDA indicator light illuminates (yellow). Displays messages on the multi-information display.)