FAIL-SAFE FUNCTION
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.
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 (Main ECU to determine controls) |
System Related | Fail-safe Operation | Driver Detectable | DTC Detection (ECU that stored DTC) |
|---|---|---|---|---|---|
| Regenerative Operation
|
Hybrid vehicle control ECU | Brake booster with master cylinder assembly | Normal driving | Master warning light illuminates. | U117087 (Hybrid vehicle control ECU) |
| Drive Torque Control
|
Hybrid vehicle control ECU | Inverter with converter assembly | Normal driving | Master warning light illuminates. | U011087 (Hybrid vehicle control ECU) |
| Drive Torque Control
|
Hybrid vehicle control ECU | Brake booster with master cylinder assembly | Normal driving | Master warning light illuminates. | U012987 (Hybrid vehicle control ECU) |
| Shift Control
|
Hybrid vehicle control ECU | Certification ECU (smart key ECU assembly) (Power supply change function) | Automatic P position change function does not operate. | Displays messages on the multi-information display. | U110787 (Hybrid vehicle control ECU) |
| Normal Charge Control
|
Hybrid vehicle control ECU |
|
Control stops. |
|
U115087 (Electric vehicle charger assembly) |
| Timer Charging Control
|
Electric vehicle charger assembly |
|
Charging is performed immediately. (Charging is not performed when the HV battery is fully charged.) | - | U015587 (Electric vehicle charger assembly) |
| Auxiliary Power Supply
|
Solar energy control unit | Hybrid vehicle control ECU | Solar charging stops. | Displays messages on the multi-information display. | U115087 (Solar energy control unit) |
| HV Battery Charging
|
Solar energy control unit |
|
Solar charging stops. | Displays messages on the multi-information display. | U011187 U115087 (Solar energy control unit) |
| Motor/Generator Control
|
|
|
|
|
U010087 U029387 U117087 (Inverter with converter assembly) |
| Battery Control
|
Battery ECU assembly |
|
Control is performed the same as when the HV battery is not installed to the vehicle. |
|
U010087 U029387 U115087 (Battery ECU assembly) |
| Anti-lock Brake System Control
|
Brake booster with master cylinder assembly | Airbag sensor assembly | Control is permitted. |
|
U0073 U0124 (Brake booster with master cylinder assembly) |
| Vehicle Stability Control / Traction Control
|
Brake booster with master cylinder assembly |
|
Control cannot be performed. |
|
U0073 U0110 U0293 (Brake booster with master cylinder assembly) |
|
|
U0073 U0124 U0126 (Brake booster with master cylinder assembly) |
|||
| Regenerative Brake Coordinate Control
|
Brake booster with master cylinder assembly |
|
Regenerative brake coordination control is stopped immediately. |
|
U0110 U0120 U0293 (Brake booster with master cylinder assembly) |
| During control: When normal control is complete, hybrid vehicle regenerative brake coordinated control is prohibited. Not during control: Control will not be started. |
|
U0124 (Brake booster with master cylinder assembly) |
|||
| During control: Control is continued with previous values and then the brake pedal control amount is gradually changed. Then, hybrid vehicle regenerative brake coordinated control is prohibited. Not during control: Control will not be started. |
|
U0073 U0124 (Brake booster with master cylinder assembly) |
|||
| Occupant Classification System
|
Airbag sensor assembly | Occupant detection ECU | SRS components do not deploy. | SRS warning light illuminates. | U0154 (Airbag sensor assembly) |
| Vehicle Speed Display | Meter circuit plate | Brake booster with master cylinder assembly | Speedometer is controlled based on a default vehicle speed of 0 km/h (0 mph). | - | U0129 (Meter circuit plate) |
| Odometer and trip meter display
|
Meter circuit plate | Brake booster with master cylinder assembly | The last displayed value remains. | - | U0129 (Meter circuit plate) |
| Fuel Gauge
|
Meter circuit plate |
|
- | - | U0129 (Meter circuit plate) |
| Reverse Warning Buzzer
|
Meter circuit plate | Hybrid vehicle control ECU | - | - | U0293 (Meter circuit plate) |
| Door Half Latch Warning
|
Meter circuit plate |
|
- | - | U0129 (Meter circuit plate) |
| Seat Belt Warning
|
Meter circuit plate |
|
- | - | U0129 U0151 U0293 (Meter circuit plate) |
| Seat Belt Warning
|
Meter circuit plate |
|
- | - | U0129 U0151 U0293 (Meter circuit plate) |
| EPS Warning Buzzer
|
Meter circuit plate | Power steering ECU assembly | - | Electronic power steering warning buzzer sounds. | U0131 (Meter circuit plate) |
| Excess Speed Warning
|
Meter circuit plate | Brake booster with master cylinder assembly | - | - | U0129 (Meter circuit plate) |
| Driving with Parking Brake Applied Warning Buzzer
|
Meter circuit plate |
|
- | - | U0129 (Meter circuit plate) |
| Airbag
|
Meter circuit plate | Airbag sensor assembly | - | SRS warning light illuminates. | U0151 (Meter circuit plate) |
| ABS Warning
|
Meter circuit plate | Brake booster with master cylinder assembly | - | ABS warning light illuminates. | U0129 (Meter circuit plate) |
| PCS
|
Meter circuit plate |
|
- | Displays messages on the multi-information display. | U0129 U1104 (Meter circuit plate) |
| LDA
|
Meter circuit plate | Forward recognition camera | - | Displays messages on the multi-information display. | U023A (Meter circuit plate) |
| Brake Warning
|
Meter circuit plate | Brake booster with master cylinder assembly | - | Brake warning light illuminates. | U0129 (Meter circuit plate) |
| MIL
|
Meter circuit plate | ECM | - | MIL illuminates. | U0100 (Meter circuit plate) |
| Electronic Power Steering Warning
|
Meter circuit plate | Power steering ECU assembly | - | EPS warning light illuminates. | U0131 (Meter circuit plate) |
| Headlight System
|
Meter circuit plate |
|
While the power switch on (IG), the current state is maintained. | - | U0182 (Meter circuit plate) |
| Slip Warning
|
Meter circuit plate | Brake booster with master cylinder assembly | - | Slip indicator light illuminates. | U0129 (Meter circuit plate) |
| Turn Signal Light
|
Meter circuit plate |
|
- | - | U0129 (Meter circuit plate) |
| ICS OFF
|
Meter circuit plate | Clearance warning ECU assembly | - | ICS OFF indicator light flashes. | - |
| Brake Override System
|
Meter circuit plate | Hybrid vehicle control ECU | - | Displays messages on the multi-information display. | - |
| EV Drive Mode Indicator
|
Meter circuit plate |
|
- | - | U0100 U0129 (Meter circuit plate) |
| SBW Malfunction Indicator
|
Meter circuit plate |
|
- | Displays messages on the multi-information display. | U0293 (Meter circuit plate) |
| Drive Monitor
|
Meter circuit plate |
|
- |
|
U0129 (Meter circuit plate) |
| Destination
|
Meter circuit plate | Main body ECU (multiplex network body ECU) | - | - | U0142 (Meter circuit plate) |
| Tire Pressure Monitor System (Tire Pressure Warning Indicator Light)
|
Meter circuit plate | Main body ECU (multiplex network body ECU) | - | Tire pressure warning light illuminates. | U0142 (Meter circuit plate) |
| Linking-up with Multi-information Display
|
Meter circuit plate |
|
Information for the navigation system, audio system, etc. is not displayed. | - | U0163 (Meter circuit plate) |
| Air Conditioning Control
|
Air conditioning amplifier assembly | ECM | Control is performed based on default coolant temperature of 80°C (176°F). | - | U0293 (Air conditioning amplifier assembly) |
| Simple Load Control
|
Air conditioning amplifier assembly | Power steering ECU assembly | While the power switch on (IG), previous values are maintained (during a reset, there is no load control). | - | U0131 (Air conditioning amplifier assembly) |
| Air Conditioning Control
|
Air conditioning amplifier assembly | Meter circuit plate | While the power switch on (IG), previous values are maintained. | - | U0155 (Air conditioning amplifier assembly) |
| Panel Dimming Control
|
Air conditioning amplifier assembly | Main body ECU (multiplex network body ECU) | While the power switch on (IG), previous values are maintained (during a reset, dimming control is performed). | - | U0142 (Air conditioning amplifier assembly) |
| Destination Determination Control
|
Air conditioning amplifier assembly | Main body ECU (multiplex network body ECU) | While the power switch on (IG), previous values are maintained. | - | U0142 (Air conditioning amplifier assembly) |
| Ambient Temperature Correction Control
|
Air conditioning amplifier assembly | Meter circuit plate | Control is performed based on default vehicle speed of 0 km/h (0 mph). | - | U0155 (Air conditioning amplifier assembly) |
| Air Conditioning Eco Mode Control
|
Air conditioning amplifier assembly | Hybrid vehicle control ECU | While the power switch on (IG), previous values are maintained (after a reset, the system stays in its normal state of operation). | - | - |
| Solar Calibration Control
|
Air conditioning amplifier assembly | Main body ECU (multiplex network body ECU) | While the power switch on (IG), previous values are maintained. | - | U0142 (Air conditioning amplifier assembly) |
| Power Switch (Power Source Control)
|
Certification ECU (smart key ECU assembly) |
|
- | Displays messages on the multi-information display. | U0103 U0129 U0140 U0164 U0293 U1135 U113A (Certification ECU (smart key ECU assembly)) |
| Blind Spot Monitor Control
|
Blind spot monitor sensor LH |
|
- | Displays messages on the multi-information display. | U0126 U0129 U0142 U0293 (Blind spot monitor sensor LH) |
| Grille Shutter Opening or Closing Operation Control
|
Swing grille actuator assembly |
|
Grille shutter opening operation is performed and further grille shutter operation is prohibited. | - | - |
| LKA/LDA/SWS System (Recognizes the lane markers of the lane the vehicle is in using the forward recognition camera and performs the following operations based on the vehicle condition and information captured by the forward recognition camera.)
|
Forward recognition camera |
|
|
|
U0101 U0123 U0126 U0129 U0131 U0142 U0155 U0235 U0293 U023A U1104 (Forward recognition camera) |
| Automatic high beam does not operate.
|
Forward recognition camera |
|
Performs control based on the signals received before the malfunction occurred. | Displays messages on the multi-information display. | U0123 U0126 U0129 U0235 U0293 (Forward recognition camera) |
| Road Sign Assist Function
|
Forward recognition camera |
|
Road sign assist function is canceled. |
|
U0101 U0123 U0129 U0142 U0155 U0293 (Forward recognition camera) |
| PCS
|
Forward recognition camera |
|
Detection processing is reset and signals indicating that the forward recognition camera is not detecting objects are sent to the driving support ECU assembly. |
|
U0123 U0129 U0142 U0235 U0293 U1104 (Forward recognition camera) |
| Cruise Control
|
Hybrid vehicle control ECU | Brake booster with master cylinder assembly | Control stops. | Displays messages on the multi-information display. | U012287 (Hybrid vehicle control ECU) |
| ACC
|
Hybrid vehicle control ECU |
|
Control stops. | Displays messages on the multi-information display. | U012287 U029387 U110487 (Hybrid vehicle control ECU) |
| ACC
|
Driving support ECU assembly |
|
Control stops. |
|
U0125 U0126 U0129 U0235 U0293 U1104 (Driving support ECU assembly) |
| PCS
|
Driving support ECU assembly |
|
Control stops. |
|
U0125 U0126 U0129 U0235 U023A U0293 U1104 (Driving support ECU assembly) |
| Entry Function
|
|
|
|
- | U0100 U0142 U0155 (Certification ECU (smart key ECU assembly)) |
| Wireless Function
|
Certification ECU (smart key ECU assembly) | Main body ECU (multiplex network body ECU) | Wireless lock/unlock function do not operate. | - | U0142 (Certification ECU (smart key ECU assembly)) |
| Power Switch Backlighting Control
|
Certification ECU (smart key ECU assembly) | Main body ECU (multiplex network body ECU) |
|
- | U0142 (Certification ECU (smart key ECU assembly)) |
| Security Indicator Display Function
|
Certification ECU (smart key ECU assembly) |
|
|
- | U0142 U0293 (Certification ECU (smart key ECU assembly)) |
| Occupant Detection | Occupant detection ECU |
|
Sends signals indicating a malfunction to the airbag sensor assembly. | SRS warning light illuminates. | U0125 U0129 (Occupant detection ECU) |
| Parking Assist Monitor Function
|
Rear television camera assembly |
|
Parking assist monitor function is prohibited. |
|
U0100 U0126 U0129 U0131 U0140 U0163 U1110 (Rear television camera assembly) |
| Air Conditioning Control
|
|
Air conditioning amplifier assembly |
|
Air conditioning connection confirmation screen is displayed. |
|
| Toyota Parking Assist-sensor System Setting/Notification
|
|
|
|
|
|
| Fuel Consumption Display
|
|
|
When communication with ECM, brake booster with master cylinder assembly or hybrid vehicle control ECU is interrupted:
When communication with meter circuit plate is interrupted:
|
- |
|
| HV Energy Flow Display
|
|
Hybrid vehicle control ECU | 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. | - |
|
| Destination Identification
|
|
Main body ECU (multiplex network body ECU) | Determines the destination according to the last received value and operates accordingly (if there is no last received value, the system operates using the default value). | Time zone and language selection screen are different from actual destination. |
|
| Rear View Monitor System
|
|
Hybrid vehicle control ECU | Screen does not change to the camera screen. | - |
|
| Simple Intelligent Parking Assist System
|
Clearance warning ECU assembly |
|
Simple intelligent parking assist control is stopped. |
|
U0073 U0100 U0124 U0126 U0129 U0131 U0155 U0164 U0293 U1000 (Clearance warning ECU assembly) |
| Intelligent Clearance Sonar System
|
Clearance warning ECU assembly |
|
Intelligent clearance sonar control is stopped. |
|
U0073 U0100 U0124 U0126 U0129 U0293 U1000 (Clearance warning ECU assembly) |
| TOYOTA Parking Assist-sensor System
|
Clearance warning ECU assembly |
|
TOYOTA parking assist-sensor control is stopped. | - | U0100 U0126 U0129 U0293 (Clearance warning ECU assembly) |
| Power Steering Control
|
Power steering ECU assembly |
|
|
EPS warning light illuminates. | U0129 U0293 (Power steering ECU assembly) |
| Assist Map Selection
|
Power steering ECU assembly |
|
Default map is used to assist because proper assist map cannot be selected. (Steering feel may be different.) | EPS warning light illuminates. | C1581 (Power steering ECU assembly) |
| VDIMα System
|
Power steering ECU assembly | Brake booster with master cylinder assembly | VDIMα control is stopped. | - | U0129 (Power steering ECU assembly) |
| LKA System
|
Power steering ECU assembly |
|
Control stops. | - | U023A (Power steering ECU assembly) |
| IPA System
|
|
|
Control stops. | - | U0129 U1110 (Power steering ECU assembly) |
| Headup Display
|
Combination meter mirror ECU | Driving support ECU assembly | Control is performed the same as when there is no display request signals. | - | U1104 (Combination meter mirror ECU) |
| Headup Display
|
Combination meter mirror ECU | Forward recognition camera | Lane markers are not displayed. | - | U023A (Combination meter mirror ECU) |
| GRS ECU
|
ECM | Swing grille actuator assembly | The grille shutter is kept fully open. | MIL illuminates.*1 | U028487 (ECM) |
| MG ECU
|
ECM | Inverter with converter assembly | Engine is stopped. | MIL illuminates. | U011087 (ECM) |
| HV ECU
|
ECM |
|
Engine is stopped. | MIL illuminates.*2 | U029387 U117587 U129387 (ECM) |
| Headlight Leveling Control (Headlight Control)
|
No. 1 headlight ECU sub-assembly LH |
|
Control stops. | - | U0100 U0129 U0142 U0293 (No. 1 headlight ECU sub-assembly LH) |
| Destination Identification
|
No. 1 headlight ECU sub-assembly LH |
|
- | - | U0100 U0142 (No. 1 headlight ECU sub-assembly LH) |
| Low Beam Headlights, High Beam Headlights, Clearance Lights and Side Marker Lights
|
No. 1 headlight ECU sub-assembly LH | Main body ECU (multiplex network body ECU) | The low beam headlights, clearance lights and side marker lights are forcibly illuminated. | - | U0142 (No. 1 headlight ECU sub-assembly LH) |
| Adaptive High Beam System
|
No. 1 headlight ECU sub-assembly LH |
|
|
- | U0101 U0126 U0129 U0142 (No. 1 headlight ECU sub-assembly LH) |
| Door Lock
|
Main body ECU (multiplex network body ECU) | Airbag sensor assembly | Key linked door lock/unlock function is performed even when the power switch is on (IG) and the driver seatbelt is fastened. | - | U0151 (Main body ECU (multiplex network body ECU)) |
| Shift-linked Automatic Door Lock Function
|
Main body ECU (multiplex network body ECU) | Hybrid vehicle control ECU | All of the doors are not locked automatically when all of the following conditions are met.
|
- | U0101 (Main body ECU (multiplex network body ECU)) |
| Shift-linked Automatic Door Unlock Function
|
Main body ECU (multiplex network body ECU) |
|
All of the doors are not locked automatically when all of the following conditions are met.
|
- | U0101 U0155 (Main body ECU (multiplex network body ECU)) |
| Speed-sensitive Automatic Door Lock Function
|
Main body ECU (multiplex network body ECU) | Meter circuit plate | All of the doors are not locked automatically when all of the following conditions are met.
|
- | U0155 (Main body ECU (multiplex network body ECU)) |
| Manual Unlock Prohibition Function
|
Main body ECU (multiplex network body ECU) |
|
|
- | U0100 (Main body ECU (multiplex network body ECU)) |
| Power Door Lock Control System Customize Setting
|
Main body ECU (multiplex network body ECU) | Hybrid vehicle control ECU |
|
- | U0101 (Main body ECU (multiplex network body ECU)) |
| Wireless Function
|
Main body ECU (multiplex network body ECU) | Certification ECU (smart key ECU assembly) | The doors cannot be locked or unlocked via remote operation. | - | - |
| Entry Lock/Unlock
|
Main body ECU (multiplex network body ECU) | Certification ECU (smart key ECU assembly) | The doors cannot be locked or unlocked via remote operation. | - | - |
| Wireless Door Lock Buzzer
|
Main body ECU (multiplex network body ECU) | Certification ECU (smart key ECU assembly) | The wireless door lock buzzer does not sound when the doors are locked/unlocked by wireless operation. | - | U0327 (Main body ECU (multiplex network body ECU)) |
| Back Door Open Function
|
Main body ECU (multiplex network body ECU) | Certification ECU (smart key ECU assembly) | When the back door open switch is pushed and held with the back door locked, the back door does not unlock or unlatch. | - | U0327 (Main body ECU (multiplex network body ECU)) |
| Dome Lights
|
Main body ECU (multiplex network body ECU) | Certification ECU (smart key ECU assembly) | The interior lights remain off when the electrical key transmitter sub-assembly is close to any of the doors. | - | U0327 (Main body ECU (multiplex network body ECU)) |
| Dimmer Controlled Illumination
|
Main body ECU (multiplex network body ECU) | Hybrid vehicle control ECU | The interior lights remain on without being dimmed when the shift state is park (P) and a shift state other than park (P) is selected. | - | U0101 (Main body ECU (multiplex network body ECU)) |
| Alarm Function
|
Main body ECU (multiplex network body ECU) |
|
|
- | U0100 U0120 U0293 (Main body ECU (multiplex network body ECU)) |
| Auxiliary Battery Saving Function
|
Main body ECU (multiplex network body ECU) | Certification ECU (smart key ECU assembly) | When the auxiliary battery is in battery saving mode and any of the doors are approached while holding an entry key, the auxiliary battery saving function is not canceled and the interior illuminations do not illuminate. | - | U0327 (Main body ECU (multiplex network body ECU)) |
| Interior Light Auto Cut Function
|
Main body ECU (multiplex network body ECU) | Certification ECU (smart key ECU assembly) | The headlights do not turn off when the lock switch of the electrical key transmitter sub assembly is pressed with all of the doors locked during the interior light auto cut function is performed. | - | - |
| Headlight System Malfunction Warning Display
|
Main body ECU (multiplex network body ECU) |
|
|
- | U0100 U0293 (Main body ECU (multiplex network body ECU)) |
| Meter Illumination Auto Dimmer
|
Main body ECU (multiplex network body ECU) | Meter circuit plate | The meter illumination is dimmed when the tail cancel switch is on. | - | U0155 (Main body ECU (multiplex network body ECU)) |
*1: w/ Occupant Classification System
*2: w/o Occupant Classification System (Even if DTC U129387 is stored, the MIL will not illuminate.)