Fail-Safe Chart
- FAIL SAFE OPERATION
- 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, TRAC 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 (See PROBLEM SYMPTOMS TABLE ).
- 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 (See PROBLEM SYMPTOMS TABLE ).
HINT:
If the hydraulic brake booster encounters a malfunction, brake performance is gradually lost and ABS, BA, TRAC and VSC systems are prohibited.
ABS, EBD and BA system:
ABS, EBD AND BA SYSTEM MALFUNCTION AREAMalfunction 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 system:
TRAC AND VSC SYSTEM MALFUNCTION AREAMalfunction Area Control Method Engine control system Before control: Disables control (TRAC and VSC systems) During control: Uses only the brakes to effect control Brake control system Before control: Disables control (VSC system) During control: Uses only the engine to effect control Brake control system Before control: Disables control (TRAC systems) During control: Disables control (by gradually ending control)
- 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.