CAN COMMUNICATION SYSTEM 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 Power steering ECU assembly The idle speed increase for an electrical load is not performed.

      Nothing

      (The idle speed changes.)
      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 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 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 Eco driving indicator ECM (for 1NR-FE and 1NZ-FE) Combination meter assembly Indicator is turned off.

      Nothing

      (Detected by the status that the indicator is turned off.)
      Engine Integrated control ECM 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 Eco Control ECM Air conditioning amplifier assembly, Combination meter assembly Eco mode does not operate.

      Nothing

      (Detected by failure of Eco mode operation.)
      Engine ECT system indicators ECM (for 1NR-FE and 1NZ-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 and 1NZ-FE) Skid control ECU (brake actuator assembly) Neutral control does not operate.

      U0129

      (Nothing)
      Engine Cruise control ECM (for 1NR-FE and 1NZ-FE) Skid control ECU (brake actuator assembly) (w/ VSC), Combination meter assembly Nothing

      Nothing

      (Indicator light blink.)
      VSC ABS control Skid control ECU (brake actuator assembly) (w/ VSC) Airbag sensor assembly

      • 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, U0124

      (Complied with FMVSS126: 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, 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 under control: Cannot start control.

      U0073, U0100, U0124, U0126

      (Complied with FMVSS126: Brake warning light comes on. ABS warning light comes on. Slip indicator light comes on.)
      VSC Eco run hill hold control (w/ Engine Stop and Start System) Skid control ECU (brake actuator assembly) (w/ VSC) ECM, Airbag sensor assembly, Engine stop and start ECU, Steering angle sensor (spiral cable sub-assembly)

      • Under control: After backup control to reduce oil pressure is completed, control is prohibited.

      • Not under control: Cannot start control.

      U0073, U0100, U0124, U0126

      (Complied with FMVSS126: Brake warning light comes on. ABS warning light comes on. Slip indicator light comes on.)

      • Under control: Control is continued and after normal control is completed, control is prohibited.

      • Not under control: Cannot start control.
      ABS

      ABS control

      (Vehicle anti-locking for sudden stops)

      		 Skid control ECU (brake actuator assembly) (w/o VSC) Main body ECU (multiplex network 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 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 Eco drive information Radio 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.)
      Main body Door lock (w/ Rear Fog Light) Main body ECU (multiplex network body ECU) ECM, Airbag sensor assembly, Combination meter assembly

      • The speed-sensitive automatic door lock operation is prohibited.

      • The shift-linked automatic door lock operation is prohibited.

      • The shift-linked automatic door unlock operation is prohibited.

      • Automatic lock switching is prohibited.

      U0100, U0151, U0155

      (Detected by failure of lock operation.)
      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) (w/ Rear Fog Light) Main body ECU (multiplex network body ECU) ECM DRL control operation fails.

      U0100

      (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 αB control Power steering ECU assembly Skid control ECU (brake actuator assembly) αB control stops.

      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 An assist map that is suitable for the vehicle cannot be selected, so assistance is performed with a temporary assist map.

      U0100

      (Indicator light comes on.)
      Certification ECU Entry function Certification ECU (smart key ECU assembly) Main body ECU (multiplex network body ECU), Combination meter assembly Perform retrying entry unlock.

      U0142, U0155

      (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.)
      Certification ECU Engine Switch Illumination Control Certification ECU (smart key ECU assembly) Main body ECU (multiplex network body ECU)

      • The engine switch illumination is lit accompanying the dome light: It turns off.

      • The engine switch illumination is lit accompanying the panel illumination while D.C.C fuse is removed: It turns off.

      U0142

      (When the engine switch illumination is lit due to the dome light: It turns off. When the engine switch illumination is lit due to the panel illumination with D.C.C fuse removed: It turns off.)
      Certification ECU Push start (switching power source) Certification ECU (smart key ECU assembly) ECM, Main body ECU (multiplex network body ECU), Engine stop and start ECU, Combination meter assembly Nothing

      U0100, U0142, U0155, U1103

      (The start operation is not displayed when necessary.)
      Engine Stop and Start ECU Stop and start system Engine stop and start ECU ECM (for 1NR-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

      • Under operation: Restarting.

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

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

      (Light blink.)
      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 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.)
      TCM Multi-mode manual transaxle system TCM ECM (for 1ND-TV)

      • Gear does not change.

      • Only possible to drive in 1st or reverse gears after vehicle stops.

      U0129

      (Gear does not change. Only possible to drive in 1st or reverse gears after vehicle stops.)