ABS CONTROL
1.

NORMAL BRAKING

Solenoid valve

State

Valve

Passage

IN (NO)

OFF

OPEN

Master cylinder ⇔ Wheel cylinder

OUT (NC)

OFF

CLOSE

Wheel cylinder ⇔ Reservoir

2.

DUMP MODE

Solenoid valve

State

Valve

Passage

IN (NO)

ON

CLOSE

Master cylinder ⇔ Wheel cylinder

OUT (NC)

ON

OPEN

Wheel cylinder ⇔ Reservoir

3.

HOLD MODE

Solenoid valve

State

Valve

Passage

IN (NO)

ON

CLOSE

Master cylinder ⇔ Wheel cylinder

OUT (NC)

OFF

CLOSE

Wheel cylinder ⇔ Reservoir

4.

INCREASE MODE

Solenoid valve

State

Valve

Passage

IN (NO)

OFF

OPEN

Master cylinder ⇔ Wheel cylinder

OUT (NC)

OFF

CLOSE

Wheel cylinder ⇔ Reservoir

TRACTION CONTROL SYSTEM (TCS)
1.

NORMAL MODE

Solenoid valve

State

Valve

Motor pump

TC valve

IN (NO)

OFF

OPEN

OFF

OFF

OUT (NC)

OFF

CLOSE

In the normal driving condition, TC valve (normally open) is the passage between the master cylinder and the each wheel cylinder.

When brake pedal is applied, brake pressure is delivered to the wheel cylinders via NO-TC valve and all solenoid valves inside the hydraulic unitare deactivated.

In case of TCS malfunction it does not affect brake operation.

2.

PRESSURE INCREASE MODE

Solenoid valve

State

Valve

Motor pump

TC valve

IN (NO)

FRONT : OFF

REAR : ON

FRONT : OPEN

REAR : CLOSE

ON

ON

OUT (NC)

OFF

CLOSE

If a front wheel spin is detected, TCS begins a brake control to decrease a wheel spin.

Hydraulic shuttle valve (HSV) is opened.

Brake fluid is supplied from the master cylinder by motor operation to the spin wheel via HSV.

TC valve is closed (ON).

Brake pressure generated from motor pump is delivered only to the front wheel.

Inlet valve remains open to deliver the brake pressure generated from motor pump to the spinning wheels.

3.

PRESSURE DUMP MODE

Solenoid valve

State

Valve

Motor pump

TC valve

IN (NO)

ON

CLOSE

ON

ON

OUT (NC)

FRONT : ON

REAR : OFF

FRONT : OPEN

REAR : CLOSE

When the wheel deceleration is under the threshold and the wheel spin is reduced under a slip threshold, applied brake pressure is reduced to geta optimum traction force.

Outlet valve is open to release the brake pressure and inlet valve is closed to block the pressure increase from the motor pump.

Hydraulic shuttle valve (HSV) remains opened, TC valve is ON.

Motor is ON, to dump the brake fluid being released from the lock-up wheel.

4.

PRESSURE HOLD MODE

Solenoid valve

State

Valve

Motor pump

TC valve

IN (NO)

ON

CLOSE

ON

ON

OUT (NC)

OFF

CLOSE

EBD (Electronic Brake-force Distribution)
ADVANTAGES
-

Function improvement of the base-brake system.

-

Compensation for the different friction coefficients.

-

Elimination of the proportioning valve.

-

Failure recognition by the warning lamp.

Comparison between Proportioning valve and EBD
FAIL SAFE

FAIL CAUSE

SYSTEM

WARNING LAMP

ABS

EBD

ABS

EBD

None

ON

ON

OFF

OFF

1-Wheel speed sensor failure

OFF

ON

ON

OFF

Pump malfunction

OFF

ON

ON

OFF

Low voltage

OFF

ON

ON

OFF

2 or more wheel speed sensor failure

OFF

OFF

ON

ON

Solenoid valve failure

HECU malfunction

Other failure

WARNING LAMP CONTROL
1.

ABS warning lamp module

The active ABS warning lamp module indicates the operating condition of the ABS.

The ABS warning lamp is turned on under the following conditions.

A.

During the initialization phase after ignition switch ON (3 seconds).

B.

In the event of inhibition of ABS functions by failure.

C.

When the system ECU is shut down even though ignition power is applied.

D.

During diagnostic mode.

2.

EBD warning lamp module

The active EBD warning lamp module indicates the operating condition of the EBD. However, in case the parking brake switch is turned on, the EBDwarning lamp is always turned on regardless of EBD functions.

The EBD warning lamp is turned on under the following conditions.

A.

During the initialization phase after ignition switch ON. (3 seconds).

B.

When the system ECU is shut down even though ignition power is applied.

C.

When the parking brake switch is ON or brake fluid is low level.

3.

TCS lamp module

The passive TCS warning lamp module indicates the operating condition of the TCS.

The TCS warning lamp is turned on under the following conditions :

A.

During the initialization phase after ignition switch ON (3 seconds).

B.

In the event of inhibition of TCS functions by failure.

C.

When the TCS OFF switch is turned on.

TCS function lamp is turned on when the TCS functions are operating (Blinking-2Hz).

Яндекс.Метрика