ELECTRONICALLY CONTROLLED BRAKE SYSTEM > FAIL-SAFE CHART

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FAIL SAFE OPERATION
  1. When trouble occurs in the brake control system, the skid control ECU comes on the warning light on, displays a DTC corresponding to the malfunctioning systems on the multi information display, and prohibits ABS, BA, and VSC operations.
  2. The skid control ECU prevents operation of a malfunctioning hydraulic pressure system and continues brake control with the normal hydraulic pressure system.

HINT:
  1. If control of the ECB for any of the 4 wheels is prohibited, that wheel loses brake booster function or braking ability.
  2. 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.
  3. If control of the ECB for all wheels is prohibited, the 2 front wheels will lose brake booster function.


ABS, EBD and BA system: 
Malfunction Area
Control Method
ABS system
ABS, BA, TR(A)C and VSC control prohibited
BA system
ABS, BA, TR(A)C and VSC control prohibited
EBD system
ABS, EBD, BA, TR(A)C and VSC control prohibited

HINT:
A malfunction in either the ABS or BA system will result in an identical operation, with ABS, BA, TR(A)C and VSC system control prohibited.


TR(A)C and VSC system: 
Malfunction Area
Control Method
Engine control system
(TR(A)C and VSC systems)
Before control: Disables control
During control: Uses only the brakes to effect control
Brake control system
(TR(A)C and VSC systems)
Before control: Disables control
During control: Disables control (by gradually ending control)

HINT:
As for the TR(A)C and VSC systems, different systems prohibit different controls depending on a malfunctioning part.