Toyota Tacoma (2015-2018) Service Manual: Fail-safe Chart

Toyota Tacoma (2015-2018) Service Manual / Can Communication / Can Communication System / Fail-safe Chart

FAIL-SAFE CHART

1. FAIL-SAFE FUNCTION

(a) 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.

(b) The following table shows the effects on each system when communication is impossible. (For further details, see the pages for each system.)

Function	Behavior during CAN Failure
Function	1. Control Master 2. System Related	Vehicle Behavior	DTC (Driver Detectable)	Diagnostic Trouble Code
VDM Control (Calculates torque level desired by driver based on accelerator pedal operation and controls torque according to this and other conditions in order to achieve smoother driving performance and improved stability, startability, reacceleration, and acceleration feel.)	1. ECM 2. Brake booster assembly (skid control ECU), Brake actuator assembly (skid control ECU), Airbag sensor assembly, Spiral cable with sensor sub-assembly	Does not calculate desired torque based on accelerator pedal operation, and does not provide smoother driving performance or improved stability, startability, reacceleration, or acceleration feel.	Nothing (Does not calculate desired torque based on accelerator pedal operation, and does not provide smoother driving performance or improved stability, startability, reacceleration, or acceleration feel.)	Nothing
ECT indicator in meter (Shift position, switch, mode, etc.)	1. ECM 2. Combination meter assembly	Indicators do not turn on.	Nothing (Indicators do not turn on.)	Nothing
AI-SHIFT control (Control the A/T in order to improve engine braking power and acceleration feeling.)	1. ECM 2. Brake booster assembly (skid control ECU), Brake actuator assembly (skid control ECU)	AI-SHIFT control does not operate.	Nothing (AI-SHIFT control does not operate.)	Nothing
Cruise control (Adjusts the engine throttle valve opening amount automatically to control the vehicle.)	1. ECM 2. Brake booster assembly (skid control ECU), Brake actuator assembly (skid control ECU), Combination meter assembly	Cruise control does not operate. Cancel the dynamic radar cruise control	Nothing (Indicator light blinks.)	Nothing
VSC control (Prevent skid when cornering)	1. Brake booster assembly (skid control ECU), Brake actuator assembly (skid control ECU) 2. ECM, Airbag sensor assembly, Spiral cable with sensor sub-assembly, millimeter wave radar sensor assembly	VSC does not operate.	(Light turns on.)	U0073 U0100 U0123 U0124 U0126
TRC control (Stabilize vehicle start.)	1. Brake booster assembly (skid control ECU), Brake actuator assembly (skid control ECU) 2. ECM, Airbag sensor assembly, Spiral cable with sensor sub-assembly	TRC does not operate.	(Light turns on.)	U0073 U0100 U0123 U0124 U0126
ABS control (Prevents wheels from locking during sudden braking.)	1. Brake booster assembly (skid control ECU), Brake actuator assembly (skid control ECU) 2. Airbag sensor assembly	ABS does not operate.	(Light turns on.)	U0073 U0123 U0124
PCS Control (Applies the brakes based on information from the radar/camera system in order to avoid a collision.)	1. Brake booster assembly (skid control ECU), brake actuator assembly (skid control ECU) 2. Millimeter wave radar sensor assembly	PCS brake control is disabled.	(Light turns on.)	U0073
ACC Control (Applies the brakes based on information from the radar/camera system in order to follow the vehicle in front.)	1. Brake booster assembly (skid control ECU), brake actuator assembly (skid control ECU) 2. ECM	ACC brake control is disabled.	(Light turns on.)	U0073
Event data recorder (Records conditions such as the vehicle speed, the amount the accelerator is depressed, and the shift lever position when the event data recorder recording conditions are met.)	1. Airbag sensor assembly 2. ECM, Combination meter assembly	An invalid value is stored.	Nothing (Cannot be detected.)	Nothing
Collision detection signal (Notifies the system of a collision in order to perform a fuel cut at the time when a vehicle collision occurs.)	1. ECM 2. Airbag sensor assembly	In the event of a collision, fuel cut is not performed.	Nothing (Cannot be detected.)	Nothing
Steering sensor (Detects the steering wheel angle.)	1. Spiral cable with sensor sub-assembly 2. Brake booster assembly (skid control ECU), Brake actuator assembly (skid control ECU)	Nothing	Nothing (VSC Indicator light turns on.)	Nothing
Blind Spot Monitor Control (Detects vehicle in blind spot of adjacent lane and informs driver.)	1. Blind spot monitor sensor LH 2. Brake booster assembly (skid control ECU), Brake actuator assembly (skid control ECU), ECM, Main body ECU (multiplex network body ECU)	Blind spot monitor control is prohibited.	Blind spot monitor system warning light on the combination meter turns on.	U0100 U0126 U0129 U0142 U0232
Air Conditioning Control (Air conditioning control controls air conditioning functions such as set temperature adjustment, air outlet selection, etc. using the remote touch.)	1. Navigation receiver assembly, Radio and display receiver assembly 2. Air conditioning amplifier assembly	When set temperature is shown on multi-display, set temperature display turns off. Air conditioning function(s) are prohibited.	A message indicating to check air conditioning amplifier connection appears on multi-display.	U0073 U0164
Intuitive Parking Assist System Setting/Notification (Controls settings for clearance sonar screen notifications which are set by operating Remote Touch, displays sonar status and plays voice warnings.)	1. Navigation receiver assembly, Radio and display receiver assembly 2. Clearance warning ECU assembly	Display updating is stopped.	-	U0073 U0100 U1110
Door Lock (Controls key linked and automatic door lock/unlock function, key confinement prevention function, etc.)	1. Main body ECU (Multiplex network body ECU) 2. Airbag sensor assembly, Combination meter assembly, ECM	Speed sensitive automatic lock control does not occur. Shift linked automatic lock control does not occur. Shift linked automatic unlock control does not occur. Automatic lock/ unlock cannot be changed.	Nothing	U0100 U0101 U0151 U0155
Alarm Control (Sounds various warnings.)	1. Main body ECU (multiplex network body ECU) 2. ECM	Nothing	Nothing	U0100
Display Automatic Dimming (Display dimming control.)	1. Main body ECU (Multiplex network body ECU) 2. Combination meter assembly	Automatic dimming control for displays does not operate when taillights are turned on.	Nothing	U0155
Illumination Control	1. Main body ECU (Multiplex network body ECU) 2. Certification ECU (smart key ECU assembly)	Interior lights turn off.	When communication with certification ECU (smart key ECU assembly) is interrupted: Interior lights do not turn off right after getting out of the vehicle.	U0327
Entry Function/Wireless Control	1. Certification ECU (Smart key ECU assembly) 2. Main body ECU (multiplex network body ECU)	Entry lock/unlock control is not possible.	Nothing	U0327
Daytime Running Light Control	1. Main body ECU (Multiplex network body ECU) 2. ECM	Daytime running light control does not operate.	Nothing	U0100
Automatic High Beam System	1. Main body ECU (multiplex network body ECU) 2. Forward recognition camera	Auto high light control does not operate (combination meter indicator blinks).	AHB indicator blinks.	U023A
Tire Pressure Monitoring System (Monitors tire pressure, vehicle speed, etc., and illuminates indicator lights or displays a message on the multi-information display.)	1. Door control and tire pressure monitoring system receiver assembly 2. Combination meter assembly	Nothing	Tire pressure warning light blinks and then illuminates.	U0155
Entry and Start Function Entry lock/unlock unlatch Entry and start warnings Entry illumination (dome light illumination, etc.) Engine start possible display	1. Main body ECU (multiplex network body ECU), Certification ECU (smart key ECU assembly) 2. Main body ECU (multiplex network body ECU), Combination meter assembly	An entry unlock retry is performed.	When transmission is abnormal: The entry lock/ unlock do not operate. The entry and start warnings (the key lock-in prevention warning, the leaving with the key warning, key reminder, etc.) and the key lock-in prevention function do not operate. Entry illumination does not operate. When there is a reception stop: The entry and start warnings (the key lock-in prevention warning, the leaving with the key warning, key reminder, etc.), the ignition switch to ON possible display, and the key lock-in prevention function do not operate. The answer back function repeats a maximum of 3 times when an unlock operation is performed. However, this only occurs when the main body ECU (multiplex network body ECU) can receive requests from the certification ECU (smart key ECU assembly). When the ignition switch to ON, the entry lock/unlock do not operate.	U0142 U0155
Entry and Start Function Entry lock/unlock unlatch Entry and start warnings Entry illumination (dome light illumination, etc.) Engine start possible display	1. Certification ECU (smart key ECU assembly) 2. ECM, Combination meter assembly	The previous value is maintained.	Incorrect entry and start warnings are output.	U0100
Wireless Function (Operates the wireless lock/unlock functions, etc.)	1. Main body ECU (multiplex network body ECU) 2. Certification ECU (smart key ECU assembly), Main body ECU (multiplex network body ECU)	Nothing	Wireless lock/ unlock and trunk functions do not operate. When the ignition switch to ON, the wireless lock/ unlock functions do not operate.	U0142
Engine Switch Lettering Illumination Control (Operates the engine switch lettering illumination in conjunction with the dome light illumination, etc.)	1. Certification ECU (smart key ECU assembly) 2. Combination meter assembly, Certification ECU (smart key ECU assembly), Main body ECU (multiplex network body ECU)	If the engine switch letters are illuminated due to the dome light, the illumination turns off. When the DC cut fuse is removed and the engine switch letters are illuminated due to the panel illumination, the illumination turns off. The previous value is maintained.	If the engine switch letters are not illuminated, they do not illuminate. If the engine switch letters are illuminated due to the panel illumination, the illumination does not turn off. If the engine switch letters are illuminated due to the dome light, the illumination turns off. When the DC cut fuse is removed and the engine switch letters are illuminated due to the panel illumination, the illumination turns off.	U0142
Security Indicator Display Function (Displays the immobiliser security condition.)	1. Certification ECU (smart key ECU assembly) 2. Certification ECU (smart key ECU assembly), Main body ECU (multiplex network body ECU)	Nothing	Security condition cannot display normally (illuminates during security warning preparation/security warning).	U0142
Vehicle Speed Display (Displays the vehicle speed on the speedometer according to the vehicle speed signal from the skid control ECU.)	1. Combination meter assembly 2. Brake booster assembly (skid control ECU), Brake actuator assembly (skid control ECU)	Signal is considered to be 0.	The speedometer displays 0 km/h (0 mph). The drive monitor stops calculating.	U0129
Tachometer (Displays information on the tachometer.)	1. Combination meter assembly 2. ECM	Signal is considered to be 0.	The tachometer displays 0 rpm. The drive monitor stops calculating.	U0100
ECT/ENG System Display (Turns the temperature gauge command high engine coolant temperature warning display on and off.)	1. Combination meter assembly 2. ECM	Signal is considered to be 0.	The engine coolant temperature warning light illuminates. Displays messages on the multi-information display.	Nothing
Airbag (Turns the SRS warning light on and off.)	1. Combination meter assembly 2. Airbag sensor assembly	Signal is considered to be "Active".	The airbag warning light illuminates.	U0151
SLIP Warning (Turns the SLIP warning light on and off.)	1. Combination meter assembly 2. Brake booster assembly (skid control ECU), Brake actuator assembly (skid control ECU)	Signal is considered to be "Active".	The SLIP indicator illuminates.	Nothing
TPMS (Turns the tire pressure warning light on and off)	1. Combination meter assembly 2. Door control and tire pressure monitoring system receiver assembly	Signal is considered to be "Active".	The TPMS warning light illuminates.	Nothing
DRL Request (Controls bulb DRL)	1. Combination meter assembly 2. Main body ECU (multiplex network body ECU)	Keep last receive state.	Nothing	U0142
Popular Name (Vehicle body type description)	1. Combination meter assembly 2. Main body ECU (multiplex network body ECU)	Keep initial value	Nothing	Nothing
Lost Communication Detection (Monitors the NS and NM frames of the ECU connected to the global bus to detect for ECU communication failures.)	1. Central gateway ECU (network gateway ECU) 2. ECUs connected to the global bus	Stores the communication failure time.	Nothing	Nothing
Automatic High Beam System (Controls the high beams.)	1. Forward recognition camera 2. Main Body ECU (Multiplex Network Body ECU), ECM, Brake Booster Assembly (Skid Control ECU), Brake Actuator Assembly (Skid Control ECU), Airbag Sensor Assembly, Spiral Cable with Sensor Sub-assembly	Keep last value Camera control continues normally. However, AHB signals cannot be sent to the Main body ECU (multiplex network body ECU). As a result, the Main body ECU (multiplex network body ECU) performs malfunction judgment and maintains the condition. Normal control is continued.	The AHB indicator illuminates (umber).	B124B U023A
Lane Departure Alert System (Warns the driver when the vehicle deviates from its lane.)	1. Forward recognition camera 2. Brake Booster Assembly (Skid Control ECU), Brake Actuator Assembly (Skid Control ECU), Main Body ECU (Multiplex Network Body ECU), Combination Meter Assembly, Airbag Sensor Assembly, Millimeter Wave Radar Sensor Assembly, Spiral Cable with Sensor Sub-assembly	The warning is stopped. White line recognition is stopped.	Displays messages on the multi-information display. The buzzer sounds	U0123 U0126 U0129 U0142 U0155 U0235
Pre-collision System (Detects obstacles in front and performs brake assist and brake control in order to lessen damage and avoid collisions.)	1. Millimeter wave radar sensor assembly 2. Brake Booster Assembly (Skid Control ECU), Brake Actuator Assembly (Skid Control ECU), Airbag Sensor Assembly, Spiral Cable with Sensor Sub-assembly, ECM, Forward Recognition Camera	Pre-collision system is stopped.	The PCS warning light blinks. Displays message on the multi-information display. The buzzer sounds.	U0100 U0125 U0126 U0129 U023A U0235 U1002
Dynamic Radar Cruise Control System (Uses the millimeter wave radar, yaw rate sensor, steering angle sensor, etc., to recognize and judge the existence of a preceding vehicle, track it, and ensure an appropriate vehicle-to-vehicle distance while driving and stopping. When there are no preceding vehicles, this system allows for constant-speed driving at the set speed.)	1. Millimeter wave radar sensor assembly 2. Brake Booster Assembly (Skid Control ECU), Brake Actuator Assembly (Skid Control ECU), Airbag Sensor Assembly, Spiral Cable with Sensor Sub-assembly, ECM	Cruise control system is stopped.	Displays message on the multi-information display.	U0100 U0125 U0126 U0129

Dtc Check / Clear

DTC CHECK / CLEAR CHECK FOR DTC (a) Connect the Techstream to the DLC3. (b) Turn the ignition switch to ON. (c) Turn the Techstream on. (d) Enter the following menus: Body Electrical / Central Ga ...

ECU Malfunction (B1003)

DESCRIPTION DTC No. DTC Detection Condition Trouble Area B1003 A malfunction in the non-volatile storage of the central gateway ECU (n ...

Other materials:

Precaution
PRECAUTION 1. IGNITION SWITCH EXPRESSIONS (a) The type of ignition switch used on this model differs according to the specifications of the vehicle. The expressions listed in the table below are used in this section. Expression Ignition Switch (Position) Engine ...

Open in Turn Signal Circuit (B1507,B1508)
DESCRIPTION This DTC is stored when the combination meter assembly detects an open in a turn signal light circuit, a short in a turn signal light circuit, or a short in the hazard warning light circuit. DTC No. DTC Detection Condition Trouble Area ...

Lost Communication with ECM/PCM "A" Missing Message (U010087)
DESCRIPTION The engine control unit and the transmission control unit are located inside the ECM. The engine control unit intercommunicates with the transmission control unit with the Controller Area Network (CAN). If there is a problem in this intercommunication, the ECM stores a DTC. ...