Fail-Safe Chart
WARNING: This page is about a different car, the 2011 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.
- FAIL-SAFE FUNCTION
- When communication fails in any of the CAN bus wires (communication wires) 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.
- The following chart shows the relationships between components, system functions, and effects of communication failure on these functions. (For further details, see appropriate service information for each system.)
Function
(Function Description)Control Master System Related Fail-safe Operation DTC
(Driver Detectable)Neutral control ECM Skid control ECU Neutral control stops U0129*3
(Impossible)Air conditioning control Air Conditioning Amplifier - ECM
- Combination Meter
- Main Body ECU
- Accessory Gateway
Air conditioning function and PTC heater function stop B1499
(Air Conditioning inoperative)VSC control*1
(Controls driving force while VSC in operation)Skid Control ECU - ECM
- Steering Angle Sensor
- Yaw Rate Sensor
VSC control is inoperative
(VSC control gradually stops)U0073, U0100, U0123, U0124, U0126
(Warning light comes on)VSC control*1
(Engine power control by VSC/TRC)Skid Control ECU - ECM
- Steering Angle Sensor
- Yaw Rate Sensor
VSC control is inoperative
(VSC control gradually stops)U0073, U0100, U0123, U0124, U0126
(Warning light comes on)ABS control*1
(Controls driving force while ABS in operation)Skid Control ECU Yaw Rate Sensor Control inoperative
(gradually stops controlling during ABS control)U0073, U0123, U0124
(Warning light comes on)ABS control*2
(Controls driving force while ABS in operation)Skid Control ECU ECM Control inoperative
(gradually stops controlling during ABS control)U0073
(Warning light comes on)Electric power steering
(Speed of vehicle induction type torque control)Power Steering ECU - ECM
- Skid Control ECU
- Steering Angle Sensor
- Combination Meter
- Accessory Gateway
VSC Malfunction: Depression of EPS assist (Deterioration of steering) U0100, U0129
(VSC failure: Warning light comes on, and decrease of assistance power at vehicle speed 70 km/h)
(ECM failure: Warning light comes on [only before assist begins])ECM Malfunction (before assist begins): stop the assist operation
ECM Malfunction (after assist begins): continue the assist operationEntry function/Power door lock control*3 Main Body ECU - ECM
- Accessory Gateway
- Center Airbag Sensor Assembly
- Combination Meter
- Certification ECU
The door lock cannot be released for smart entry U0327, U1002
(Wireless door lock cannot operate)Immobilizer control*3
(Alarm control and remote engine start control)Certification ECU - ECM
- Accessory Gateway
- Air Conditioning Amplifier
- Combination Meter
- Main Body ECU
The engine starting is not possible by smart entry U0327, U1002
(Possible)Meter display (Displays operation condition and DTCs) Combination Meter - ECM
- Skid Control ECU
- Power Steering ECU
- Center Airbag Sensor Assembly
- Certification ECU
- Main Body ECU
Light does not come on, illuminates abnormally, or blinks abnormally U0100, U0129
(Abnormal light illumination)Buzzer control (sounds the buzzer in the combination meter according to a buzzer sounding request from each ECU) Combination Meter - ECM
- Skid Control ECU
- Power Steering ECU
- Main Body ECU
- Certification ECU
Buzzer function stops None
(Abnormal light illumination)*1: w/ VSC
*2: w/o VSC
*3: w/ Smart key system