CAN COMMUNICATION SYSTEM(w/o 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)
      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 1NR-FE) 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 1NR-FE 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 1NR-FE 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 1NR-FE) Combination meter assembly Indicator is turned off.

      Nothing

      (Detected by the status that the indicator is turned off.)
      Engine Integrated control ECM (for 1NR-FE and 1ND-TV) Skid control ECU (brake actuator assembly) (w/ VSC), 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) (w/ VSC) Torque request from skid control ECU (brake actuator assembly) is not accepted.

      Nothing

      (Nothing)
      Engine Eco Control ECM (for 1NR-FE) 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 1NR-FE) 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 1NR-FE) Skid control ECU (brake actuator assembly) Neutral control does not operate.

      U0129

      (Nothing)
      Engine Cruise control (w/ Cruise Control System)

      • ECM (for 1NR-FE)

      • Driving support ECU (for 1ND-TV)

      		 Skid control ECU (brake actuator assembly) (w/ VSC), Combination meter assembly Nothing

      Nothing

      (Indicator light blink.)
      Airbag Event Recorder Center airbag sensor assembly ECM, Skid control ECU (brake actuator assembly An invalid value is stored

      Nothing

      (Nothing)
      VSC VSC control, ABS control, TRC control, MSR control, ESS control Skid control ECU (brake actuator assembly) (w/ VSC) ECM, Airbag sensor assembly, Steering angle sensor (spiral cable sub-assembly)

      • Under control: After backup control to stabilize the vehicle behavior is completed, the normal brake is switched to and control is prohibited.

      • Not during control: Control cannot be performed.

      U0073, U0100, U0123, U0124, U0126, U0142

      (Brake warning light comes on. ABS warning light comes on. Slip indicator light comes on. Not during control: Control cannot be performed.)
      ABS ABS control Skid control ECU (brake actuator assembly) (w/o VSC) Main body ECU

      • Under control: After backup control to stabilize the vehicle behavior is completed, the normal brake is switched to and control is prohibited.

      • Not under control: Cannot start control.

      U0073, U0142

      (ABS warning 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) (w/ VSC), 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.)
      EPS Electronic power steering system Power steering ECU assembly Skid control ECU (brake actuator assembly) Control is performed temporarily with the steering assist amount set to that used when the vehicle speed is 70 km/h.

      U0129

      (Indicator light comes on.)
      EPS Assist calculation Power steering ECU assembly Skid control ECU (brake actuator assembly) Because the vehicle speed cannot be detected, control is temporarily continued assuming 70 km/h. If the speed is below 70 km/h, the steering wheel will feel heavy. If the speed is above 70 km/h, the steering wheel will feel light.

      U0129

      (Indicator light comes on.)
      EPS Assist map selection Power steering ECU assembly ECM, Skid control ECU (brake actuator assembly) An assist map that is suitable for the vehicle cannot be selected, so assistance is performed with a temporary assist map.

      Nothing

      (Indicator light comes on.)
      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 1NR-FE and 1KR-FE), 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, 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.)
      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) (w/ VSC) 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 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) (w/ VSC) Signal is treated as active.

      Nothing

      (Indicator light comes on.)