Title: NETWORKING: CAN COMMUNICATION SYSTEM: FAIL-SAFE CHART (2012 Camry HV)

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

Control Master

System Related

Fail-safe Operation

Driver Detectable

DTC Detection
(ECU that stored DTC)

Power steering control
Calculates assist current according to torque sensor value and vehicle speed and drives motor

Power steering ECU assembly

Power management control ECU
Brake booster with master cylinder assembly (Skid control ECU)

Control is performed based on default assist current for a vehicle speed of 140 km/h (87 mph).
Drivability degrades (compensation control using steering angle is stopped).

EPS warning light illuminates.

U0129
U0293
(Power steering ECU assembly)

Steering assist calculation
Changes assist force based on vehicle speed

Power steering ECU assembly

Power management control ECU
Brake booster with master cylinder assembly (Skid control ECU)

When communication with skid control ECU is interrupted:
Control continues based on a default speed of 140 km/h (87 mph) because vehicle speed is unrecognizable.

EPS warning light illuminates.

U0129
U0293
(Power steering ECU assembly)

Assist map selection
Selects proper assist map according to destination, engine type, etc.

Power steering ECU assembly

ECM
Brake booster with master cylinder assembly (Skid control ECU)

Default map is used to assist because proper assist map cannot be selected. (Steering feel may be different.)

EPS warning light illuminates.

-

Steering assist compensation control
Provides steering assist with compensation amount based on vehicle speed

Power steering ECU assembly

Brake booster with master cylinder assembly (Skid control ECU)

Control is performed based on a default vehicle speed of approximately 140km/h (87 mph).

EPS warning light illuminates.

U0129
(Power steering ECU assembly)

Air conditioning Eco mode control

  • Performs control in Eco mode using B_ECOMI

Air conditioning amplifier assembly

Power management control ECU

Maintains the latest state (Maintained in normal condition after reset)

-

U0293
(Air conditioning amplifier assembly)

Fuel Consumption display

  • Displays graph of fuel consumption per minute and history of total fuel consumption
  • Navigation ECU sub-assembly*1*2
  • Radio and display receiver assembly*3
  • Brake booster with master cylinder assembly (Skid control ECU)
  • Combination meter assembly
  • ECM
  • Power management control ECU

When communication with ECM or skid control ECU is interrupted:

  • Display is not updated.

When communication with combination meter is interrupted:

  • Display is not updated.
  • Numeric part of driveable mileage is cleared.

-

-

HV energy flow display

  • Creates energy flow screen which indicates regeneration status and drive force transmission status
  • Navigation ECU sub-assembly*1*2
  • Radio and display receiver assembly*3

Power management control ECU

If communication stops while the energy flow screen is displayed, the energy flow display disappears and the latest value is maintained for the SOC (state of charge) level display.

-

U0293
(Navigation ECU sub-assembly*1*2)
(Radio and display receiver assembly*3)

Parking assist monitor control

  • Displays rear view monitor based on steering sensor, vehicle speed and vehicle information

Navigation ECU sub-assembly*2
  • Steering sensor
  • Main body ECU (Multiplex network body ECU)

When communication with steering angle sensor is interrupted:

  • Message is shown indicating that guide lines cannot be displayed.

-

U0073
U0126
U0140
(Navigation ECU sub-assembly*2)

Vehicle customization function

  • Allows changing of operation and control conditions for vehicle functions via multi-display operation
  • Navigation ECU sub-assembly*1*2
  • Radio and display receiver assembly*3
  • Main body ECU (Multiplex network body ECU)
  • Smart key ECU assembly (Certification ECU)
  • Air conditioning amplifier assembly

When an application that uses phase 4 remote communication is activated (customization/remote diagnosis), the process will be performed regardless of main body ECU (multiplex network body ECU) remote communication permit/prohibit state.

-

U0140
(Navigation ECU sub-assembly*1*2)
(Radio and display receiver assembly*3)

Door lock

  • Controls key linked and automatic door lock/unlock function, key confinement prevention function, etc.

Main body ECU (Multiplex network body ECU)
  • Combination meter assembly
  • ECM
  • Power management control ECU
  • 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.

-

U0100
U0101
U0155
(Main body ECU (Multiplex network body ECU))

Display automatic dimming

  • Display dimming control

Main body ECU (Multiplex network body ECU)

Combination meter assembly

Automatic dimming control for displays does not operate when taillights are turned on.

-

U0155
(Main body ECU (Multiplex network body ECU))

Luggage compartment door opener/luggage compartment door open control

  • (Accepts luggage compartment door opener request)

Main body ECU (Multiplex network body ECU)
  • Combination meter assembly
  • ECM
  • Power management control ECU

Luggage compartment door does not open.

-

U0100
U0101
U0155
(Main body ECU (Multiplex network body ECU))

Illumination control

Main body ECU (Multiplex network body ECU)
  • Smart key ECU assembly (Certification ECU)
  • Power management control ECU
  • Interior lights turn off.
  • Inside handle light turn off.

When communication with smart key ECU is interrupted:

  • Interior lights do not turn off right after getting out of the vehicle.

U0293
U0327
(Main body ECU (Multiplex network body ECU))

Entry function/wireless control

Smart key ECU assembly (Certification ECU)

Main body ECU (Multiplex network body ECU)

Entry lock/unlock control is not possible.

-

U0327
(Main body ECU (Multiplex network body ECU))

Drive torque control
Controls the engine, MG1 and MG2 based on engine information received

Power management control ECU

ECM

Vehicle drives using only the motor

Displays messages on the multi-information display.

U0100
(Power management control ECU (Hybrid control system))

Regenerative operation
Provides maximum amount of regeneration based on cooperative control with the ECB system

Power management control ECU

Brake booster with master cylinder assembly (Skid control ECU)

Regeneration is prohibited.

Displays messages on the multi-information display.

U0129
(Power management control ECU (Hybrid control system))

High voltage shut off control when the vehicle is damaged
Receives the SRS collision detection signal (CDT-HV) and shuts off the system main relays

Power management control ECU

Airbag sensor assembly

Normal driving

Displays messages on the multi-information display.

U0151
(Power management control ECU (Hybrid control system))

HV system power processing
Determines that an IG2 malfunction cannot be judged when a power supply ECU communication error occurs

Power management control ECU (Hybrid control system)

Power management control ECU (Power management control CPU)

Normal driving

Displays messages on the multi-information display.

U1107
(Power management control ECU (Hybrid control system))

Air conditioning control
Sends a signal from the air conditioning amplifier assembly to the power management control ECU (HV CPU) and from the power management control ECU (HV CPU) to the inverter for the air conditioning system.

Air conditioning amplifier assembly

Power management control ECU

Air conditioning cooling operation is stopped.

-

U0164
(Power management control ECU)

Engine start/stop switch (Power source mode change)

  • Using start/stop switch signal as trigger, changes power source mode automatically and requests starter operation when conditions are met

Power management control ECU (Power management control CPU)
  • Main body ECU (Multiplex network body ECU)
  • Combination meter assembly
  • Power management control ECU (Hybrid control system)

None

-

U0140
U0155
U0293
(Power management control ECU (Power management control CPU))

Cruise control

  • Calculates demand drive force to maintain vehicle speed

Power management control ECU

Brake booster with master cylinder assembly (Skid control ECU)

Cruise control is canceled.
  • Displays messages on the multi-information display.
  • Master warning light turns on.

U0122
(Power management control ECU)

PTC heater

  • When there is a heat demand signal that requires operation of the PTC heater (including heating from coolant), idle up is performed.

Air conditioning amplifier assembly

ECM
  • Engine idle speed changes.
  • Heating performance deteriorates.
  • PTC heater does not operate.

-

-

Charge control

  • Performs idle up according to charging request

Power management control ECU

Air conditioning amplifier assembly

Idle up according to charging request is not performed.

Taillights flicker and blower airflow changes.

-

Entry function

  • Entry lock/unlock, entry luggage compartment open
  • Warning
  • Performs entry illumination (Interior illumination etc)
  • Main body ECU (Multiplex network body ECU)
  • Smart key ECU assembly (Certification ECU)
  • Main body ECU (Multiplex network body ECU)
  • Combination meter assembly

Entry unlock is performed again.

Entry lock/unlock or entry luggage compartment open does not operate.
Warning functions (Key confinement, Key not in vehicle, Key reminder etc.) do not operate, Key confinement prevention control does not operate.
Entry illumination does not operate.

U0327
(Main body ECU (Multiplex network body ECU))
U0142
U0155
(Smart key ECU assembly (Certification ECU))

Wireless function

  • Locks and unlocks doors etc. via remote operation

Main body ECU (Multiplex network body ECU)

Smart key ECU assembly (Certification ECU)

Wireless lock, unlock and luggage compartment opener do not operate.

-

U0142
(Smart key ECU assembly (Certification ECU))

Power switch backlighting control

  • Turns on/off power switch illumination linked with interior lights etc.

Smart key ECU assembly (Certification ECU)

Main body ECU (Multiplex network body ECU)

power switch backlighting does not illuminate according to interior lights operation

-

U0142
(Smart key ECU assembly (Certification ECU))

Vehicle speed display

Combination meter assembly

Brake booster with master cylinder assembly (Skid control ECU)

Speedometer is controlled based on a default vehicle speed of 0 km/h (0 mph).
  • The needle points at 0 km/h (0 mph).
  • Drive monitor calculation is stopped.

U0129
(Combination meter assembly)

Airbag
(Airbag warning light control)

Combination meter assembly

Airbag sensor assembly

None

Airbag warning light illuminates.

U0151
(Combination meter assembly)

EPS warning
(EPS warning light control)

Combination meter assembly

Power steering ECU assembly

None

EPS warning light illuminates.

U0131
(Combination meter assembly)

SLIP warning
(SLIP warning light control)

Combination meter assembly

Brake booster with master cylinder assembly (Skid control ECU)

None

SLIP indicator illuminates.

-

ABS/TRC/VSC control

Brake booster with master cylinder assembly (Skid control ECU)
  • Airbag sensor assembly (built-in type yaw rate sensor)
  • Yaw rate sensor (separate type yaw rate sensor)
  • When control is being performed: When back-up control (vehicle behavior stabilization) is complete, braking returns to normal operation and further control is prohibited.
  • When control is not being performed: Control will not be started.
  • Brake warning light (red) illuminates.
  • ABS warning light illuminates.
  • SLIP indicator illuminates.
  • Brake warning light (yellow) illuminates.

U0073
U0123
U0124
U0126
U0293
(Brake booster with master cylinder assembly (Skid control ECU))

HAC2 control

  • Maintains brake pressure for 2 seconds when the brake pedal has been depressed further after stopping the vehicle

Brake booster with master cylinder assembly (Skid control ECU)
  • Power management control ECU
  • Steering sensor
  • Airbag sensor assembly
  • When control is being performed: Once control (depressurization control) has completed, further hill-start assist control is prohibited.
  • When control is not being performed: Hill-start assist control does not start.
  • Brake warning light (red) illuminates.
  • ABS warning light illuminates.
  • SLIP indicator illuminates.
  • Brake warning light (yellow) illuminates.

U0073
U0123
U0124
U0126
U0293
(Brake booster with master cylinder assembly (Skid control ECU))

Hybrid regenerative operation

  • Regenerative cooperative control with the HV system

Brake booster with master cylinder assembly (Skid control ECU)

Power management control ECU
  • When control is being performed: HV cooperative control is continued based on the latest value and gradually decreased. After this, HV cooperative control is prohibited.
  • When control is not being performed: HV cooperative control does not start.
  • Brake warning light (red) illuminates.
  • ABS warning light illuminates.
  • SLIP indicator illuminates.
  • Brake warning light (yellow) illuminates.

U0073
U0293
(Brake booster with master cylinder assembly (Skid control ECU))

Blind spot monitor control

  • Detects vehicle in blind spot of adjacent lane and informs driver

Blind spot monitor sensor RH
  • Steering sensor
  • Brake booster with master cylinder assembly (Skid control ECU)
  • Main body ECU (Multiplex network body ECU)
  • Power management control ECU

Control stops

Displays messages on the multi-information display.

U0100
U0126
U0129
U0142
U0232
U0293
(Blind spot monitor sensor RH)

Blind spot monitor sensor LH
  • Steering sensor
  • Brake booster with master cylinder assembly (Skid control ECU)
  • Main body ECU (Multiplex network body ECU)
  • Power management control ECU

Control stops

Displays messages on the multi-information display.

U0100
U0126
U0129
U0142
U0233
U0293
(Blind spot monitor sensor LH)

Gateway system (between V bus and sub bus 11)

  • Relays data between V bus and sub bus 11, and monitors ECUs connected to sub bus 11

Power management control ECU
  • Blind spot monitor sensor LH
  • Blind spot monitor sensor LH

-

-

U0232
U0233
U1002
(Power management control ECU (Gateway system))

HINT:

  • *1: for Navigation receiver type
  • *2: for Radio and display type (w/ Intuitive parking assist system)
  • *3: for Radio and display type (w/o Intuitive parking assist system)