Vehicle Stability Control System Fail-Safe Chart

  1. FAIL-SAFE OPERATION

Vehicle Stability Control System -- Fail-Safe Chart



FAIL-SAFE OPERATION
  1. If there is a problem with sensor signals or brake actuator systems, the skid control ECU 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 stops its VSC (traction control signal), which is based on signals from the skid control ECU. The vehicle operates in a manner similar to a vehicle that is not equipped with ABS, TRC, and VSC systems.
    ABS control will be prohibited, but EBD control will continue to the extent that EBD is possible. If EBD control is impossible, the brake warning light will come on to warn the driver.
  2. If a system component has any malfunction before control begins, operation is prohibited. If a system component has any malfunction during control, the system will gradually stop operating 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 system control termination (Toyota Fortuner RM000000XHK044X.html).
HINT:
If the brake booster encounters a malfunction, brake performance is gradually lost and the ABS, BA, TRC and VSC systems are prohibited.

ABS, EBD and BA system
Malfunctioning Area
Control Method
ABS
ABS, BA, TRC and VSC system prohibited
BA system
ABS, BA, TRC and VSC system prohibited
EBD system
ABS, EBD, BA and TRC system prohibited
HINT:
A malfunction in either the ABS or BA system will result in identical operation, with ABS, BA, TRC and VSC system control prohibited.

TRC and VSC system
Malfunctioning Area
Control Method
Engine control system
(TRC and VSC systems)
Before control: Disables control
During control: Uses only the brakes to effect control
Brake control system
(VSC system)
Before control: Disables control
During control: Uses only the engine to effect control
Brake control system
(TRC system)
Before control: Disables control
During control: Disables control (by gradually stopping control)
HINT:
The TRC and VSC systems use different systems to prohibit different controls depending on the malfunctioning parts.