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Fail-Safe Chart

Fig 1: Fail Safe Chart
G02918125Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  1. FAIL-SAFE FUNCTION 
  1. If a malfunction occurs in the skid control ECU, sensor signal, or actuator, rest normally operating parts will maintain brake control.
  2. 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.
  3. A power back-up unit is built in as an additional power source to supply stable power to the system.
  4. If the regenerative brake alone does not operate under such conditions as a communication error with the HV ECU, control is switched so that all braking force is generated with the hydraulic pressure brake.
FAILSAFE FUNCTION

Trouble 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