Fail-Safe Chart
- FAIL-SAFE FUNCTION
- If a malfunction occurs in the skid control ECU, sensor signal, or actuator, rest normally operating parts will maintain brake control.
- When trouble occurs in the brake control system, the skid control ECU turns the warning light on, displays a DTC corresponding to the malfunctioning systems on the multi information display, and prohibits ABS, BA, and VSC operations.
ABS, EBD and BA system:
FAIL-SAFE FUNCTION CHARTMalfunction Area Control Method ABS system ABS, BA, TRAC and VSC control prohibited BA system ABS, BA, TRAC and VSC control prohibited EBD system ABS, EBD, BA, TRAC and VSC control prohibited HINT:
A malfunction in either the ABS or BA system will result in an identical operation, with ABS, BA, TRAC and VSC system control prohibited.
TRAC and VSC system:
FAIL-SAFE FUNCTION CHARTMalfunction Area Control Method Hybrid control system (TRAC and VSC systems) Before control: Disables control During control: Uses only the brakes to effect control Brake control system (TRAC and VSC systems) Before control: Disables control During control: Disables control (by gradually ending control) HINT:
As for the TRAC and VSC systems, different systems prohibit different controls depending on a malfunctioning part.
- The skid control ECU prevents operation of a malfunctioning hydraulic pressure system and continues brake control with the normal hydraulic pressure system.
HINT:
- If control of the Electronically Controlled Brake for any of the 4 wheels is prohibited, that wheel loses brake booster function or braking ability.
- If one of the 4 wheels loses brake booster function, the feeling when depressing the brake pedal changes as the stroke simulator (pedal reactive force generating solenoid) operation will be prohibited.
- If control of the Electronically Controlled Brake for all wheels is prohibited, the 2 front wheels will lose brake booster function.
- If the brake control is stopped under such conditions as when trouble occurs with a hydraulic pressure source, the pressure generated in the master cylinder by the driver is applied to the wheel cylinder to ensure braking force.
- A power back-up unit is built in as an additional power source to supply stable power to the system.
- If the regenerative brake alone does not operate under such conditions as a communication error with the HV control ECU, control is switched so that all braking force is generated with the hydraulic pressure brake.
HYDRAULIC PRESSURE SPECIFICATIONMalfunction Area Generated Braking Force Skid control ECU Normally operating parts will control brake and generate braking force Hydraulic pressure controlling parts Normally operating parts will control brake and generate braking force Hydraulic pressure source Braking force generated by the driver