Vehicle Stability Control System (For Hatchback With Separate Type Yaw Rate Sensor) Fail-Safe Chart

Brake. Yaris. Ncp93, 131
Brake Control Dynamic Control Systems. Yaris. Ncp93, 131

  1. FAIL-SAFE OPERATION

Vehicle Stability Control System (For Hatchback With Separate Type Yaw Rate Sensor) -- Fail-Safe Chart



FAIL-SAFE OPERATION
  1. If there is a problem with sensor signals or actuator systems, the skid control ECU (brake actuator assembly) prohibits power supply to the brake actuator assembly and informs the ECM of VSC system failure.
    The brake actuator assembly turns off each solenoid and the ECM shuts off VSC control (traction control signal) from the skid control ECU (brake actuator assembly) accordingly, which turns out to be as if the ABS, TRAC and VSC systems were not installed.
    The ABS control will be prohibited, but EBD control will continue as much as possible. If EBD control is impossible, the brake warning light will come on to warn the driver (YARIS_NCP93 RM000000XHP0CIX.html).
  2. If system components have any malfunctions before starting control, immediately stop the operation. If system components have any malfunctions during control, gradually stop the control so as not to trigger a sudden change in vehicle conditions.
    If it is impossible to control the systems, the warning light comes on to inform the driver of termination of the systems (YARIS_NCP93 RM000000XHP0CIX.html).
HINT:
If the brake booster encounters a malfunction, brake performance is gradually lost and ABS, BA, TRAC and VSC systems are prohibited.

ABS, EBD and BA Systems
Malfunction 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 Systems
Malfunction Area
Control Method
Engine control system
(TRAC system)
Before control: Disables control
During control: Uses only the brakes to perform control
Brake control system
(VSC system)
Before control: Disables control
During control: Uses only the engine to perform control
Brake control system
(TRAC system)
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 the malfunctioning part.