VEHICLE STABILITY CONTROL SYSTEM > FAIL-SAFE CHART

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FAIL SAFE OPERATION
  1. If there is a problem with sensor signals or actuator systems, the skid control ECU prohibits power supply to the ABS and TRACTION actuator assembly and informs the ECM of VSC system failure.
    The ABS and TRACTION actuator assembly turns off each solenoid and the ECM shuts off VSC control (traction control signal) from the skid control ECU accordingly, which turns out to be as if the ABS, TR(A)C and VSC systems were not installed.
    The ABS control will be prohibited, but EBD control continues as much as possible. If EBD control is impossible, the BRAKE warning light comes on to warn the driver (Click here).
  2. If system components have any malfunction before starting control, immediately stop the operation. If system components have any malfunction 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 (Click here).

HINT:
If the hydraulic brake booster encounters a malfunction, brake performance is gradually lost and ABS, BA, TR(A)C and VSC systems are prohibited.


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
(VSC system)
Before control: Disables control
During control: Uses only the engine to effect control
Brake control system
(TR(A)C systems)
Before control: Disables control
During control: Disables control (by gradually ending control)