Fail-Safe Chart

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: FAIL-SAFE CHART

1. FAIL-SAFE OPERATION

* If there is a problem with sensor signals or hydraulic brake booster systems, the skid control ECU prohibits power from being supplied to the hydraulic brake booster and informs the ECM of VSC system failure.

The hydraulic brake booster turns off each solenoid and the ECM stops its VSC (traction control signal), which is based on signals from the skid control ECU. As a result, it is as if the ABS, TRAC and VSC systems are not installed in the vehicle.

ABS control is prohibited, but EBD control continues to the extent that it is possible. If EBD control is impossible, the BRAKE warning light comes on to warn the driver Diagnosis System.

* 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 indicator lights come on or blink to inform the driver of termination of control of the systems Diagnosis System.

HINT
If the hydraulic brake booster encounters a malfunction, brake performance is gradually lost and ABS, BA, TRAC, A-TRAC, AUTO LSD, VSC, downhill assist control, hill-start assist control, crawl control and multi-terrain select control system controls are prohibited.

(a) ABS, EBD and BA system:





(b) TRAC, A-TRAC, VSC, AUTO LSD, downhill assist control, hill-start assist control and crawl control system:

HINT
The TRAC, A-TRAC, VSC, AUTO LSD, downhill assist control, hill-start assist control and crawl control systems each prohibit different controls depending on the malfunctioning part.





2. SYSTEM TEMPERATURE PROTECTION OPERATION

If the TRAC, A-TRAC, AUTO LSD, downhill assist control, hill-start assist control or crawl control system has been used constantly for a long time, the temperature of the hydraulic brake booster may increase excessively. If the temperature increases excessively, the skid control buzzer sounds intermittently. If the temperature increases even more, the skid control buzzer sounds for 3 seconds and the TRAC OFF indicator light comes on.





HINT
If the systems automatically return to normal operating conditions, the TRAC OFF indicator light goes off. As this is not a malfunction, no DTC is stored.