Lexus IS250 IS220d GSE20 ALE20 - BRAKE CONTROL
VEHICLE STABILITY CONTROL SYSTEM (w/ VDIM) - 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 brake actuator assembly and informs the ECM of VSC system failure.
The brake 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, TRC 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 .
The brake 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, TRC 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 .
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 .
If it is impossible to control the systems, the warning light comes on to inform the driver of termination of the systems .
- HINT:
- If the hydraulic brake booster encounters a malfunction, brake performance is gradually lost and ABS, BA, TRC and VSC systems are prohibited.
| Malfunction Area | Control Method |
| ABS system | ABS, BA, TRC and VSC control prohibited |
| BA system | ABS, BA, TRC and VSC control prohibited |
| EBD system | ABS, EBD, BA, TRC and VSC control prohibited |
- HINT:
- A malfunction in either the ABS or BA system will result in an identical operation, with ABS, BA, TRC and VSC system control prohibited.
| Malfunction Area | Control Method |
| Engine control system (TRC and VSC systems) | Before control: Disables control During control: Uses only the brakes to effect control |
| Brake control system (TRC and VSC systems) | Before control: Disables control During control: Disables control (by gradually ending control) |
- HINT:
- As for the TRC and VSC systems, different systems prohibit different controls depending on a malfunctioning part.
LEXUS IS250, IS220d / GSE20 ALE20