Fail-Safe Chart

FAIL-SAFE FUNCTION

When communication fails in any of the CAN bus lines (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.

The following table shows the relationships between components and system functions and effects of communication failure on these functions. (For further details, see the pages for each system.)

COMPONENTS AND SYSTEM FUNCTIONS RELATIONSHIPS CHART

Function	ECM	Brake actuator (Skid Control ECU)	ABS and Traction Actuator (Skid Control ECU)	Steering Sensor	Yaw Rate Sensor	Condition when communication impossible	DTC detection (Driver detectable)
VSC control (Controls driving force while VSC in operation)*2	◦		•	◦	◦	Control inoperative (gradually stops controlling during VSC control)	Detectable (Light comes on)
TRC control (Controls driving force and engine power when wheel slip detected during acceleration)*2	◦		•	◦(*1)	◦(*1)	Control inoperative (gradually stops controlling during TRC control)	Detectable (Light comes on)
ABS control (Controls driving force while ABS in operation)		•	•		◦(*2)	Control is inoperative (gradually stops controlling during ABS control)	Detectable (Light comes on)
Electric power steering (Outputs assist current)	◦	◦	◦			Steering force slightly increased at less than 70 km/h (43 5 mph) Steering force slightly reduced at 70 km/h (43 5 mph) or more	Detectable (Light comes on)
Event recorder (Tracks event data such as vehicle speed and accelerator opening angle and records data)	◦					Data not recorded	None
Air conditioning control PTC heater control	◦					Air conditioning function stops PTC heater function stops	None (Air conditioning inoperative)
Meter Display (Displays operation condition and DTCs)	◦	◦	◦			Light does not come on, illuminates abnormally, or blinks abnormally	Detectable (Abnormal display)
Buzzer control	◦	◦	◦			Buzzer function stops	None (Light comes on)
Illumination control						Light illumination rheostat inoperative	None (Rheostat inoperative)
Power door lock control	◦					Unlock permitted	None (Wireless door lock cannot operate)
HINT: •: Control master ◦: System related 1: When CAN communication failures occur in the steering sensor and the yaw rate sensors, the operations of VSC and TRC are prohibited. 2: For vehicles with VSC only.

COMPONENTS AND SYSTEM FUNCTIONS RELATIONSHIPS CHART

Function	Power Steering ECU	Center Airbag Sensor Assembly	Air Conditioning Amplifier	Combination Meter ECU	Main Body ECU	Condition when communication on impossible	DTC detection (Driver detectable)
VSC control (Controls driving force while VSC in operation)*2						Control inoperative (gradually stops controlling during VSC control)	Detectable (Light comes on)
TRC control (Controls driving force and engine power when wheel slip detected during acceleration)*2						Control inoperative (gradually stops controlling during TRC control)	Detectable (Light comes on)
ABS control (Controls driving force while ABS in operation)						Control is inoperative (gradually stops controlling during ABS control)	Detectable (Light comes on)
Electric power steering (Outputs assist current)	•					Steering force slightly increased at less than 70 km/h (43 5 mph) Steering force slightly reduced at 43 5 mph (70 km/h) or more	Detectable (Light comes on)
Event recorder (Tracks event data such as vehicle speed and accelerator opening angle and records data)		•		◦		Data not recorded	None
Air conditioning control PTC heater control			•	◦		Air conditioning function stops PTC heater function stops	None (Air conditioning inoperative)
Meter Display (Displays operation condition and DTCs)	◦	◦		•	◦	Light does not come on, illuminates abnormally, or blinks abnormally	Detectable (Abnormal display)
Buzzer control		◦		•	◦	Buzzer function stops	None (Light comes on)
Illumination control				◦	•	Light illumination rheostat inoperative	None (Rheostat inoperative)
Power door lock control				◦	•	Unlock permitted	None (Wireless door lock cannot operate)
HINT: •: Control master ◦: System related HINT: *2: For vehicles with VSC only.