1. TRC control
The hydraulic pressure that is generated by the pump is regulated by the master cylinder cut solenoid valve to the required pressure. Thus, the wheel cylinder of the drive wheels is controlled in the following 3 modespressure reduction, pressure holding, and pressure increase modes, to restrain the slippage of the drive wheels. As shown in the bottom graph at left, when the drive wheel speed begins to surpass the control start speed, the brake hydraulic pressure is increased and the number of fuel cut cylinders is increased. Therefore, it reduces the drive wheel speed.
2. VSC control
The VSC, by way of solenoid valves, controls the hydraulic pressure that is generated by the pump and applies it to the brake wheel cylinder of each wheel in the following 3 modespressure reduction, pressure holding, and pressure increase modes. As a result, the tendency to front wheel skid or rear wheel skid is restrained.
If the Skid Control ECU detects a malfunction in the ABS with EBD, BA, TRC, and VSC, the ABS, brake system, VSC warning lights and TRC OFF indicator light that corresponds to the function in which the malfunction has been detected indicates or lights up, as indicated in the table at the left, to alert the driver of the malfunction. At the same time, the DTCs (Diagnosis Trouble Codes) are stored in memory. The DTCs can be read by connecting the hand-held tester to the DLC3 to communicate with the ECU directly or causing a short between TC and CG terminals of the DLC3 and observing the blinking pattern of the ABS warning light and VSC warning light.
This system has a sensor signal check function. The sensor signals can be read by connecting the handheld tester to the DLC3 or causing a short between TS and CG terminals of the DLC3 and observing the blinking pattern of the ABS warning light and VSC warning light.
For details on the DTCs that are stored in Skid Control ECU memory and the DTCs that are output through the sensor check function, refer to the Repair Manual.
Yaw rate sensor and deceleration sensor zero point calibration needs to be performed after the battery terminal is disconnected or the yaw rate sensor or deceleration sensor are replaced. Refer to the Repair Manual for information regarding the setting method.