SsangYong Rodius (2013 year). Manual - part 170

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3. ABS SYSTEM OPERATION

1) Block Diagram

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2) EBD (Electronic Brake Force Distribution) System

▶System description

As an add-on logic to the ABS base algorithm, EBD works in a range in which the intervention 

thresholds for ABS control are not reached yet.

EBD ensures that the rear wheels are sensitively monitored for slip with respect to the front axle. If slip 

is detected, the inlet valves for the rear wheels are switched to pressure hold to prevent a further 

increase in pressure at the rear-wheel breaks, thus electronically reproducing

a pressure-reduction function at the rear-wheel brakes.

ABS features an enhanced algorithm which includes control of the brake force distribution between the 

front and rear axles. This is called Electronic Brake Distribution. In an unloading car condition the brake 

efficiency is comparable to the conventional system but for a fully loaded vehicle the efficiency of the 

EBD system is higher due to the better use of rear axle braking capability.

▶Advantages

Elimination of conventional proportioning valve EBD utilizes the existing rear axle wheel speed 

sensor to monitor rear wheel slip.

Based on many variables in algorithm a pressure hold, increase and/or decrease pulsetrain may 

be triggered at the rear wheels insuring vehicle stability.

Vehicle approaches the ideal brake force distribution (front to rear).

Constant brake force distribution during vehicle lifetime.

EBD function is monitored via ABS safety logic (conventional proportioning valves are not 

monitorable).

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3) Important Notice

The modulators for production line are not filled with the brake fluid (dry type). But, for after service, they 

are filled with the brake fluid (wet type).

Make sure to keep the procedures in service manual when bleeding the air from the brake lines.

Be familiar with the lamp ON conditions to provide the correct information and reliability to customers. 

ECU monitors the valve and motor for ABS when the vehicle speed approaches 5 km/h. At this time, 

you can hear the clattering noise.

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4. HYDRAULIC CIRCUIT DIAGRAM

1) Hydraulic Circuit of ABS 

The vehicle equipped only with the ABS controls the wheel’s braking force using three 3-

channel 4-sensor method. The front wheels that are the primary circuit of the brake system is 

composed of two wheel speed sensors and two channel valves system with two inlet valves and two 

outlet valves. The rear wheels that are the secondary circuit of the brake system is composed of two 

wheel speed sensors, one inlet valve and one outlet valve. This system is similar to the one from the 

previous model. 

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2) ABS Circuit Per ABS Operation Range

▶Hydraulic Pressure Circuit when ABS is Not Operating

The hydraulic pressure in the master cylinder increases through the vacuum booster and it is delivered 

to the wheel via the normal open inlet valve. At this moment, the normally-closed outlet valve is closed. 

The speed of the wheel that hydraulic pressure is delivered reduces gradually.

▶No Hydraulic Pressure Circuit when ABS is Operating

As hydraulic pressure on each wheel increases, the wheel tends to lock. In order to prevent the wheel 

from locking, the hydraulic valve modulator operates the inlet valve control solenoid to close the inlet 

valve and stop the hydraulic pressure increases. At this moment, the outlet valve is closed. This 

procedure helps the wheel to maintain a stable hydraulic pressure.