Fail-Safe Chart

WARNING: This page is about a different car, the 2007 Lexus ES 350. 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), 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 chart 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.)

FAIL-SAFE CHART

Function (Function Description)	Control Master	System Related	Fail-safe Operation	DTC (Driver Detectable)
ACM control (Controls active engine mount to reduce engine vibration)	Active control engine mount ECU	ECM Skid Control ECU Air Conditioning Amplifier	ACM control stops	P16A4 (Engine vibration increases)
VSC control (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 (VSC warning Light comes on)
Buzzer control	Combination Meter	ECM Skid Control ECU Center Airbag Sensor Assembly Certification ECU Main Body ECU Distance Control ECU	Buzzer function stops	U0100, U0129 (Buzzer does not sound)
Meter display (Displays operation condition and DTCs)	Combination Meter	ECM Skid Control ECU Center Airbag Sensor Assembly Certification ECU Main Body ECU AFS ECU Distance Control ECU Seat Belt Control ECU	Light does not come on, illuminates abnormally, or blinks abnormally	U0100, U0129 (Abnormal light illumination)
Air conditioning control	Air Conditioning Amplifier	ECM Combination Meter Main Body ECU Multi-display	Air conditioning function and PTC heater function stop	B1499 (Air conditioning inoperative)
Smart entry/Power door lock control	Certification ECU	Combination Meter Main Body ECU	Unlock permitted	B1207, B2326 (Wireless door lock cannot operate)
Security function	Certification ECU	Main Body ECU	Security function is inoperative (Theft deterrent system cannot be set)	B1207, B2326 (Security indicator light does not come on)
Clearance sonar function (Informs driver when an obstacle is detected)	Clearance Warning ECU	ECM Combination Meter Main Body ECU Navigation Control ECU	Clearance sonar function stops	None (Clearance sonar main switch indicator does not come on)
Mirror surface adjustment/power retracting function	Outer Mirror Control ECU	Main Body ECU	Mirror surface adjustment/ power retracting function is inoperative	None (Mirror adjustment inoperative)
Mirror automatic retracting/mirror tilt reverse-link function	Outer Mirror Control ECU	ECM Main Body ECU	Mirror automatic retracting/mirror tilt reverse-link function is inoperative	None (Mirror adjustment inoperative)
Door mirror foot light illumination function	Outer Mirror Control ECU	Main Body ECU Certification ECU	Foot illumination is inoperative	None (Foot illumination inoperative)
D seat, mirror, tilt and telescopic positions memorizing/restoring function	Seat Position Control ECU (Front LH Side)	ECM Combination Meter Main Body ECU Outer Mirror Control ECU Multiplex Tilt and Telescopic ECU	Positions cannot be memorized or restored	None (Position memorizing/ restoring function inoperative)
Memory call registration/restoration function (Registration/restoration of positions for each smart/ wireless key)	Seat Position Control ECU (Front LH Side)	Main Body ECU Certification ECU Outer Mirror Control ECU Multiplex Tilt and Telescopic ECU	Positions cannot be registered or restored	None (Position registration/restoration inoperative)
P seat position memorizing/restoring function	Seat Position Control ECU (Front RH Side)	ECM Combination Meter Main Body ECU	Position cannot be memorized or restored	None (Position memorizing/restoring function inoperative)
Auto away/return function (Moves the steering wheel based on the engine switch condition)	Multiplex Tilt and Telescopic ECU	Combination Meter Main Body ECU	Auto away/return function is inoperative	None (Auto away/return function inoperative)
AFS control (Headlight left/right angle control)	AFS ECU	ECM Skid Control ECU Steering Angle Sensor Main Body ECU	Swivel control stops/leveling control continues	B2427 (AFS OFF indicator blinks)
Dynamic radar cruise control (Maintains vehicle-to-vehicle distance)	Distance Control ECU	ECM Skid Control ECU Steering Angle Sensor Yaw Rate Sensor	Vehicle-to-vehicle distance control does not operate	U0100, U0122, U0123, U0126 (Master warning light comes on, warning message is displayed on multi-information display, and warning buzzer sounds)
Pre-collision control (Requests seat belt tightening when an unavoidable collision possibility is detected)	Seat Belt Control ECU	Skid Control ECU Center Airbag Sensor Assembly Distance Control ECU	Pre-collision system is inoperative	U0122, U0151, U1101 (PCS warning light comes on)
CAN MS bus monitoring function	Main Body ECU	Certification ECU Outer Mirror Control ECU Seat Position Control ECU (Front LH Side) Seat Position Control ECU (Front RH Side) Multiplex Tilt and Telescopic ECU Clearance warning ECU	Communication error is detected	B1207, B1213, B1272, B1276, B1297, B1289, B2326 (Not detectable)
CAN No. 2 bus monitoring function	Gateway ECU	AFS ECU Distance Control ECU Seat Belt Control ECU	Communication error is detected	U0182, U1002, U1100, U1102 (Not detectable)