Vehicle Stability Control System Fail-Safe Chart

Brake. Land Cruiser. Urj200, 202 Grj200 Vdj200
Brake Control Dynamic Control Systems. Land Cruiser. Urj200, 202 Grj200 Vdj200

  1. FAIL-SAFE OPERATION

  1. SYSTEM TEMPERATURE PROTECTION OPERATION

Vehicle Stability Control System -- Fail-Safe Chart



FAIL-SAFE OPERATION
  1. If there is a problem with sensor signals or hydraulic brake booster systems, the skid control ECU (master cylinder solenoid) 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 (master cylinder solenoid). As a result, the vehicle is controlled as if the ABS, TRC and VSC systems were 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).
  2. 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).
HINT:
If the hydraulic brake booster encounters a malfunction, brake performance is gradually lost and ABS, BA, A-TRC, VSC, hill-start assist control, Crawl Control and multi-terrain select controls are prohibited.

  1. ABS, EBD and BA system:

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

  2. A-TRC, VSC, hill-start assist control and Crawl Control system:

    HINT:
    The A-TRC, VSC, hill-start assist control and Crawl Control systems each prohibit different controls depending on the malfunctioning part.

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

SYSTEM TEMPERATURE PROTECTION OPERATION
If the A-TRC, 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 buzzer sounds intermittently. If the temperature increases even more, the buzzer sounds for 3 seconds and the TRC OFF indicator light comes on.

System
Indicator Condition
A-TRC or hill-start assist control
The TRC OFF indicator light comes on.
Crawl Control
The TRC OFF indicator light comes on.
The CRAWL indicator light blinks, and then turns off.
HINT:
If the systems automatically return to normal operating conditions, the TRC OFF indicator light goes off. As this is not a malfunction, no DTC is stored.