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 | System Related | Fail-safe Operation | Driver Detectable | DTC Detection (ECU that stored DTC) |
|---|---|---|---|---|---|
| Anti-lock Brake System Control
|
Skid control ECU (brake actuator assembly) | Airbag sensor assembly |
|
|
U0073 U0124 (Skid control ECU (brake actuator assembly)) |
| Vehicle Stability Control / Traction Control
|
Skid control ECU (brake actuator assembly) |
|
|
|
U0073 U0100 U0124 U0126 (Skid control ECU (brake actuator assembly)) |
| Hill-start Assist Control
|
Skid control ECU (brake actuator assembly) |
|
|
|
U0073 U0100 U0124 U0126 (Skid control ECU (brake actuator assembly)) |
| Air Conditioning Control
|
Air conditioning amplifier assembly | ECM |
|
- | - |
| Air Conditioning Control
|
Air conditioning amplifier assembly | Combination meter assembly |
|
- | - |
| Compressor Control
|
Air conditioning amplifier assembly | ECM | Control is performed based on default engine speed of 0 rpm. | - | - |
| Panel Dimming Control
|
Air conditioning amplifier assembly | Main body ECU (multiplex network body ECU) | Dimming mode and non-dimming mode cannot be switched. | - | - |
| Destination Identification Control
|
Air conditioning amplifier assembly | Main body ECU (multiplex network body ECU) | Maintains the latest state. | - | - |
| Intuitive Parking Assist System Setting/Notification
|
|
|
Clearance sonar screen is turned off. | - | U0100 (Navigation receiver assembly) U0100 (Radio and display receiver assembly) |
| Fuel Consumption Display
|
|
|
|
- | U0100 U0155 (Navigation receiver assembly) U0100 U0155 (Radio and display receiver assembly) |
| Parking Assist Monitor Control
|
|
|
None | Screen does not change to the camera screen. | U0100 U0140 (Navigation receiver assembly) U0100 U0140 (Radio and display receiver assembly) |
| Destination Identification
|
|
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 (Navigation receiver assembly) U0140 (Radio and display receiver assembly) |
| Vehicle Customization Function
|
|
|
|
Related customization items are not displayed or do not change to set values. | B15F5 B15F6 B15F7 U0073 (Navigation receiver assembly) B15F5 B15F6 B15F7 U0073 (Radio and display receiver assembly) |
| Time Stamp Function
|
|
Main body ECU (multiplex network body ECU) | None | - | U0073 U0140 (Navigation receiver assembly) U0073 U0140 (Radio and display receiver assembly) |
| Smart Camera Function
|
|
|
Camera diagnosis screen and camera screen are turned off. | - | - |
| Warning Sound Volume Adjustment Function
|
|
Combination meter assembly | Sound volume reduction control is canceled. | - | - |
| Door Lock
|
Main body ECU (multiplex network body ECU) |
|
|
- | U0100 U0101 U0151 U0155 (Main body ECU (multiplex network body ECU)) |
| Alarm
|
Main body ECU (multiplex network body ECU) |
|
Alarm cannot be sounded. | - | U0100 U0120 U0230 (Main body ECU (multiplex network body ECU)) |
| Display Automatic 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
|
Main body ECU (multiplex network body ECU) | Certification ECU (smart key ECU assembly) |
|
The dome light does not turn off immediately after the doors are opened and closed. | U0327 (Main body ECU (multiplex network body ECU)) |
| Seat and Mirror Control | Main body ECU (multiplex network body ECU) |
|
|
- | U0101 U0120 U0155 U0199 U0200 U0208 U0327 (Main body ECU (multiplex network body ECU)) U0142 (Certification ECU (smart key ECU assembly)) |
| Entry Function/Wireless Control | Certification ECU (smart key ECU assembly) | Main body ECU (multiplex network body ECU) | Entry lock/unlock control is not possible. | - | U0327 (Main body ECU (multiplex network body ECU)) |
| Light Control
|
Main body ECU (multiplex network body ECU) | ECM | The daytime running light control does not operate. | - | U0100 (Main body ECU (multiplex network body ECU)) |
| Back Door Opener
|
Main body ECU (multiplex network body ECU) |
|
|
- | U0155 U0230 (Main body ECU (multiplex network body ECU)) |
| Automatic Headlight Beam Level Control System
|
Main body ECU (multiplex network body ECU) | Headlight leveling ECU assembly | Maintains the same condition. | Headlamp leveling indicator light flashes. | U0182 (Main body ECU (multiplex network body ECU)) |
| Electrical Load Control
|
ECM |
|
Idle up according to the electrical load is not performed. | Engine idle speed changes. | - |
| Air Conditioning Cooperative Operation
|
ECM | Air conditioning amplifier assembly | Air conditioning system does not use cooperative controls. | Air conditioning system does not operate. | - |
| PTC Heater
|
ECM | Air conditioning amplifier assembly | PTC heater does not operate. |
|
- |
| Charge Control
|
ECM | Air conditioning amplifier assembly |
|
|
- |
| Eco Driving Indicator
|
ECM | Combination meter assembly | - | No information is displayed. | - |
| Eco Control
|
ECM | Combination meter assembly | - | Indicator does not illuminate. | - |
| Neutral Control
|
ECM |
|
Neutral control is not performed. | - | - |
| Coast Downshift Timing Change According to Air Conditioning Load
|
ECM | Air conditioning amplifier assembly |
|
- | - |
| Cruise Control
|
ECM |
|
Cruise control does not operate. | Displays messages on the multi-information display. | - |
| Electronic Power Steering System
|
Power steering ECU assembly |
|
|
EPS warning light illuminates. | U0100 U0129 (Power steering ECU assembly) |
| αB Control
|
Skid control ECU (brake actuator assembly) | Power steering ECU assembly | When CAN data of the brake actuator assembly becomes invalid during αB control, the control is stopped. | EPS warning light illuminates. | U0129 (Power steering ECU assembly) |
| Steering Assist Calculation
|
Power steering ECU assembly | Skid control ECU (brake actuator assembly) |
|
EPS warning light illuminates. | U0129 (Power steering ECU assembly) |
| Assist Map Selection
|
Power steering ECU assembly | Skid control ECU (brake actuator assembly) |
|
EPS warning light illuminates. | C1581 (Power steering ECU assembly) |
| Steering Assist Compensation Control
|
Power steering ECU assembly | Skid control ECU (brake actuator assembly) | Control is performed based on a default vehicle speed of approximately 140 km/h (87 mph). | EPS warning light illuminates. | U0129 (Power steering ECU assembly) |
| Entry Function
|
|
|
Entry unlock is performed again. |
|
U0100 U0142 U0155 (Certification ECU (smart key ECU assembly)) |
| Wireless Function
|
Main body ECU (multiplex network body ECU) |
|
- | Wireless lock and unlock do not operate. | U0142 (Certification ECU (smart key ECU assembly)) |
| Engine Switch Illumination Control
|
Certification ECU (smart key ECU assembly) |
|
|
|
U0142 (Certification ECU (smart key ECU assembly)) |
| Security Indicator Display Function
|
Certification ECU (smart key ECU assembly) |
|
- | Security status cannot be displayed correctly (security indicator blinks or illuminates when in armed state or alarm sounding state). | U0142 (Certification ECU (smart key ECU assembly)) |
| Engine Start/Stop Switch (Power Source Mode Change)
|
Certification ECU (smart key ECU assembly) |
|
- | A message urging engine start operation is not displayed when required. | U0100 U0140 U0155 (Certification ECU (smart key ECU assembly)) |
| 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 (Certification ECU (smart key ECU assembly)) |
| Vehicle Speed Display
|
Combination meter assembly | Skid control ECU (brake actuator assembly) | Control is performed based on signal value of 0. |
|
U0129 (Combination meter assembly) |
| Meter Display
|
Combination meter assembly |
|
Lights do not illuminate or lights remain illuminated. | Abnormal light operation. | U0100 U0131 U0142 U0151 U0182 U023A U1104 (Combination meter assembly) |
| Buzzer
|
Combination meter assembly |
|
Buzzer stops sounding or does not sound. | None | U0131 (Combination meter assembly) |
| Multi-information Display
|
Combination meter assembly |
|
|
None | U0100 U0129 U0131 U0142 U023A U1104 (Combination meter assembly) |
| Tachometer
|
Combination meter assembly | ECM | Control is performed based on signal value of 0. |
|
U0100 (Combination meter assembly) |
| 4WD Control
|
4WD ECU assembly |
|
|
4WD warning light illuminates. | U0073 U0100 U0126 U0129 (4WD ECU assembly) |
| Headlight Leveling Control (Headlight Control)
|
Headlight leveling ECU assembly |
|
Headlight leveling is not performed. | Displays messages on the multi-information display. | U0100 U0129 U0142 (Headlight leveling ECU assembly) |
| Seat Position Memory System
|
Position control ECU and switch assembly |
|
Controls the seat position based on operation conditions. | - | - |
| Illumination Control
|
|
Main body ECU (multiplex network body ECU) | Mirror foot illumination is turned off. | - | U0142 (Outer mirror control ECU assembly) |
| Mirror Operation Control
|
|
Main body ECU (multiplex network body ECU) | Manual mirror operation is prohibited. | - | U0142 (Outer mirror control ECU assembly) |
| Mirror Heaters
|
|
|
Mirror heaters do not operate. | - | U0142 (Outer mirror control ECU assembly) |
| Mirror Retract/Return Operation
|
|
Main body ECU (multiplex network body ECU) | Mirrors cannot be retracted or returned. | - | - |
| Mirror Surface Position Memory and Recall
|
|
Main body ECU (multiplex network body ECU) | Mirror surface position cannot be memorized or recalled. | - | - |
| Dynamic Radar Cruise Control System
|
ECM |
|
Control stops. | Displays messages on the multi-information display. | U0125 U0126 U0129 (ECM) |
| Shift Position Judgment
|
Clearance warning ECU assembly | ECM | Control operates with the default shift position (P). | - | U0101 (Clearance warning ECU assembly) |
| Toyota Parking Assist-sensor System Control
|
Clearance warning ECU assembly | Combination meter assembly | Obstacle detection is stopped. | - | U0155 (Clearance warning ECU assembly) |
| Voice Warning Availability Confirmation
|
Clearance warning ECU assembly | Main body ECU (multiplex network body ECU) | Assumes that there is no voice warning. | - | - |
| Power Back Door Automatic Opening/Closing Function
|
Multiplex network door ECU |
|
|
- | - |
| Wireless One Motion Function
|
Multiplex network door ECU |
|
Wireless one motion function is prohibited. | - | - |
| Back Door Opener Function
|
Multiplex network door ECU |
|
Back door opener function is prohibited. | - | - |
| Back Door Closer System
|
Multiplex network door ECU |
|
Power back door does not operate in reverse direction when the closer is operating. | - | - |
| Pre-crash Safety System
|
Driving support ECU assembly |
|
Control stops. |
|
U0125 U0129 U0142 (Driving support ECU assembly) |
| Lane Departure Alert System
|
Lane departure warning camera |
|
Lane departure and buzzer warning are canceled. | Displays messages on the multi-information display. | U0101 U0123 U0129 U0142 U0155 (Lane departure warning camera) |
| Automatic High Beam System
|
Lane departure warning camera |
|
Maintains the same condition. | Displays messages on the multi-information display. | U0101 U0123 U0129 U0142 (Lane departure warning camera) |
| Blind Spot Monitor Control
|
Blind spot monitor sensor LH |
|
None | Displays messages on the multi-information display. | U0100 U0126 U0129 U0142 (Blind spot monitor sensor LH) |
| Parking Assist Monitor
|
Television camera assembly |
|
Parking assist monitor function is prohibited. |
|
U0100 U0126 U0129 U0131 U0140 U0163 U1110 (Television camera assembly) |