VEHICLE STABILITY CONTROL SYSTEM (for Hydraulic Brake Booster) FAIL-SAFE CHART

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, TRC 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 Click here.

• If system components have any malfunction before starting control, immediately stop the operation.

  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 Click here.

1. ABS, EBD system and BA system:

   Malfunction Area	Control Method
   ABS	ABS, BA, TRC, A-TRC, VSC, downhill assist, hill-start assist, crawl and multi-terrain select control are prohibited
   BA system	ABS, BA, TRC, A-TRC, VSC, downhill assist, hill-start assist, crawl and multi-terrain select control are prohibited
   EBD system	ABS, BA, EBD, TRC, A-TRC, VSC, downhill assist, hill-start assist, crawl and multi-terrain select control are prohibited

2. TRC, A-TRC, VSC, downhill assist control, hill-start assist control and crawl control system:

   Tech Tips

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

   Malfunction Area	Control Method
   Engine control system (TRC and VSC systems)	Before control: Disables control During control: Uses only brakes to perform control
   Brake control system (VSC system)	Before control: Disables control During control: Uses only engine to perform control
   Brake control system (TRC, A-TRC, downhill assist control, hill-start assist control and crawl control systems)	Before control: Disables control During control: Disables control (by gradually ending control)

SYSTEM TEMPERATURE PROTECTION OPERATION

If the TRC, A-TRC, 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 increase excessively, the skid control buzzer sounds intermittently. If the temperature increases even more, the skid control buzzer sounds for 3 seconds and the TRC OFF indicator light comes on.