Fail-Safe Chart

FAIL-SAFE FUNCTION

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

Effects on each system when communication is impossible. (For further details, refer to each system.)

FAIL-SAFE CHART

System	Function/ Control	ECM	Hybrid Vehicle Control ECU	Skid Control ECU	Steering Angle Sensor	Yaw Rate Sensor	Power Steering ECU	Distance Control ECU	Behavior during communication stop	Driver-based diagnostic detection
Regenerative cooperation demand control			A	B					Regenerative brake control prohibition	Indicator displays "HV-Caution"
Vehicle torque control processing based on VDIM			A	B					VDIM control prohibition	Indicator displays "HV-Caution"
ABS operation control			B	A					ABS operation control prohibition	Indicator displays "HV-Caution"
Inclination judgment control	Sliding prevention function is performed		B	A					Even on level road, inclination judgment control is performed	Indicator displays "HV-Caution"
HV-ENG cooperative control	Based on power demand from hybrid vehicle control ECU, engine controls electronic throttle	A	B						Vehicle motivity deteriorates or MIL illuminates	MIL illuminates
Airbag control	Collision judgment is performed		A						No noticeable change	Indicator displays "HV-Caution"
Electric heater operation control	Electric heater operation prohibition demand		A						No noticeable change	None in particular
Engine ON control	Engine ON timing is divided by ventilation system		A						Engine control is performed regardless of ventilation condition	Indicator displays "HV-Caution"
VSC control	VSC or TRC engine output control is used		B	A	B	B			VSC function stops	Possible (light illuminates)
VDM-β control	Steering cooperative control			A	B	B	B		VDM-β function stops	Possible (light illuminati on malfunctions)
Dynamic radar cruise	Maintains constant distance between vehicles		A	B	B	B		A	Dynamic radar cruise control does not operate	Possible (light illuminates)
PCS and AVS control	When PCS is operating, AVS damping force becomes stiff		B		B	B		A	Control does not operate	None
Pre-collision	During vehicle collision judgment, performs brake operation demand and seat belt tighten demand		B	A	B	B		A	Pre-collision does not operate	Possible (light illuminates)
AVS control	Based on vehicle behavior data, optimizes damping force		B	B	B				Control stops	Possible (non-operation)
Electronic power steering	Calculates assist current based on torque sensor value and vehicle speed, and outputs it to motor			B	B		A		While driving with hybrid system active, or until hybrid system activates while driving without hybrid system, power steering does not operate. Continuously controls vehicle with assist power equivalent to assist power when vehicle speed is 100 km/h (60 mph)	Possible (light illuminates)
Obstacle position detection	Performs contact avoidance judgment based on steering operation				B				Informs of obstacle in detection range	Clearance warning indicator (clearance sonar sensor main switch) and handle guide mark blink
VGRS control	Controls steering gear ratio based on vehicle speed			B	B	B	B		VGRS function stops	Possible (smart warning light illuminati on malfunctions)
Active stabilizer control	Front and rear roll control		B	B	B	B			Control stops	Possible (displays of multi-information display)

HINT:

A: Control master
B: Multiplex signal transmission

FAIL-SAFE CHART

System	Function / Control	Absorber Control ECU	Seat Belt Control ECU	Clearance Warning ECU	Active Stabilizer Control ECU	Steering Control ECU	HV with Built-in Gateway	Network Gateway ECU	Behavior during communication stop	Driver-based diagnostic detection
Regenerative cooperation demand control									Regenerative brake control prohibition	Indicator displays "HV-Caution"
Vehicle torque control processing based on VDIM									VDIM control prohibition	Indicator displays "HV-Caution"
ABS operation control									ABS operation control prohibition	Indicator displays "HV-Caution"
Inclination judgment control	Sliding prevention function is performed								Even on level road, inclination judgment control is performed	Indicator displays "HV-Caution"
HV-ENG cooperative control	Based on power demand from hybrid vehicle control ECU engine controls electronic throttle								Vehicle motivity deteriorates or MIL illuminates	MIL illuminates
Airbag control	Collision judgment is performed							C	No noticeable change	Indicator displays "HV-Caution"
Electric heater operation control	Electric heater operation prohibition demand							C	No noticeable change	None in particular
Engine ON control	Engine ON timing is divided by ventilation system							C	Engine control is performed regardless of ventilation condition	Indicator displays "HV-Caution"
VSC control	VSC or TRC engine output control is used								VSC function stops	Possible (light illuminates)
VDM-β control	Steering cooperative control					B			VDM-β function stops	Possible (light illuminati on malfunctions)
Dynamic Radar cruise	Maintains constant distance between vehicles					B	C	C	Dynamic radar cruise control does not operate	Possible (light illuminates)
PCS and AVS control	When PCS is operating, AVS damping force becomes stiff	B					C	C	Control does not operate	None
Pre-collision	During vehicle collision judgment, performs brake operation demand and seat belt tighten demand		A					C	Pre-collision does not operate	Possible (light illuminates)
AVS control	Based on vehicle behavior data, optimizes damping force	A				B	C		Control stops	Possible (non-operation)
Electronic power steering	Calculates assist current based on torque sensor value and vehicle speed and outputs it to motor								While driving with hybrid system active, or until hybrid system activates while driving without hybrid system, power steering does not operate. Continuously controls vehicle with assist power equivalent to assist power when vehicle speed is 100 km/h (60 mph)	Possible (light illuminates)
Obstacle position detection	Performs contact avoidance judgment based on steering operation			A		B			Informs of obstacle in detection range	Clearance warning indicator (clearance sonar sensor main switch) and handle guide mark blink
VGRS control	Controls steering gear ratio based on vehicle speed					A			VGRS function stops	Possible (smart warning light illumination malfunctions)
Active stabilizer control	Front and rear roll control				A	B	C		Control stops	Possible (displays of multi-information display)

HINT:

A: Control master
B: Multiplex signal transmission
C: Gateway function