Fail-Safe Specification

FAIL-SAFE SPECIFICATION

Part 1:

Part 2:

Part 3:

Part 4:

The tables describe the failure location, the failure cause, the condition for detection, the failure code, the management of failure detected and the detect mode.

DETECT MODE
A: Initial check
B: Outside the ABS control cycle
C: Inside the ABS control cycle
D: Diagnosis mode
E: Failure mode

THE ABILITY OF DETECTING A FAILURE
+: Detect the failure
-: Not detect the failure

THE MANAGEMENT OF FAILURE DETECTION
1. System down. Both the ABS (TCS) and the EBD function are inhibited and the ABS (TCS) and the EBD warning lamps are activated. If this happens, the valve relay and all solenoids are prevented from being switched on.
2. Only the ABS (TCS) function is inhibited. The ABS (TCS) warning lamp is activated and the EBD warning lamp is not activated.
3. Sensor failure outside the ABS control cycle.
1) Only one sensor fails: take the same action as management 2.
2) More than two sensors fail: take the same action as management 1.
4. Sensor failure inside the ABS control cycle.
1) One front sensor fails: inhibit the ABS control of the failed-wheel and maintain ABS control of the normal wheels.
After the controller completes the ABS control, take the same action as in management 2.
2) One rear sensor fails: inhibit ABS control of both front wheels and the pressure of both rear wheels is decreased.
After the controller completes the ABS control, take the same action as in management 2.
3) More than two sensor fail: take the same action as in management 1.
5. Low operating voltage
1) Outside the ABS control cycle: inhibit the ABS (TCS) control of front wheels and allow ABS control of rear wheels, deactivating the motor. The ABS (TCS) warning lamp is directly switched on.
When the voltage recovers to the normal operating range, enable the ABS function and the ABS (TCS) warning lamp is switched off and erases the error code of low voltage.
2) Inside the ABS control cycle: inhibit the ABS control of the front wheels and allow the the ABS control of rear wheels, deactivating the motor.
The ABS (TCS) warning lamp is directly switched on and remains on. The error code is always stored.
6. Motor error during the ABS control cycle. Inhibit the ABS control of front wheels, allow ABS control of the rear wheels and ABS (TCS) warning lamp is switched ON at the end of ABS control.
7. TCS failure
Inhibit the TCS control and allow the ABS/EBD control. Meanwhile, stop checking the TCS switch failure under the TCS control.