Traction Control System

TRACTION CONTROL SYSTEM (TCS)

1. NORMAL MODE





A. In the normal driving condition, TC valve (normally open) is the passage between the master cylinder and the each wheel cylinder.
B. When brake pedal is applied, brake pressure is delivered to the wheel cylinders via NO-TC valve and all solenoid valves inside the hydraulic unit are deactivated.
C. In case of TCS malfunction, it does not affect brake operation.




2. PRESSURE INCREASE MODE





A. If a front wheel spin is detected, TCS begins a brake control to decrease a wheel spin.
B. Hydraulic shuttle valve (HSV) is opened.
Brake fluid is supplied from the master cylinder by motor operation to the spin wheel via HSV.
C. TC valve is closed (ON).
Brake pressure generated from motor pump is delivered only to the front wheel.
D. Inlet valve remains open to deliver the brake pressure generated from motor pump to the spinning wheels.




3. PRESSURE DUMP MODE





A. When the wheel deceleration is under the threshold and the wheel spin is reduced under a slip threshold, applied brake pressure is reduced to get an optimum traction force.
B. Outlet valve is open to release the brake pressure and inlet valve is closed to block the pressure increase from the motor pump.
C. Hydraulic shuttle valve (HSV) remains opened, TC valve is ON.
D. Motor is ON, to dump the brake fluid being released from the lock-up wheel.




4. PRESSURE HOLD MODE