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4E-2 ABS AND TCS
ABS(ANTI-LOCK BRAKE SYSTEM)
When wheel slip is noted during a brake application,
the ABS enters antilock mode. During antilock braking,
hydraulic pressure in the individual wheel circuits is
controlled in order to prevent any wheel from slipping.
A separate hydraulic line and specific solenoid valves
are provided for each wheel. The ABS can decrease,
hold or increase hydraulic pressure to each wheel
brake. However, the ABS cannot increase hydraulic
pressure above the amount which is transmitted by
the master cylinder during braking.
During antilock braking, a series of rapid pulsations
will be felt in the brake pedal. These pulsations are
caused by the rapid changes in position of the
individual solenoid valves as they respond to their
desired wheel speed. This pedal pulsation is present
during antilock braking and stops when normal braking
is resumed or when the vehicle comes to a stop. A
ticking or popping noise may also be heard as the
solenoid valves rapidly cycle. During antilock braking
on dry pavement, the tires may make intermittent
chirping noises as they approach slipping. These
noises and pedal pulsations should be considered
normal during antilock operation.
The vehicle may be stopped by applying normal force
to the brake pedal. Brake pedal operation during
normal braking should be no different than previous
systems. Maintaining a constant force on the pedal
will provide the shortest stopping distance while
maintaining vehicle stability.
Basic Knowledge Required
Before using this section, it is important that you have
a basic knowledge of the following items. Without this
knowledge, it will be difficult to use the diagnostic
procedures contained in this section.
Basic Electrical Circuits - You should understand the
basic theory of electricity and know the meaning of
voltage, current (amps) And resistance (ohms). You
should understand what happens in a circuit with an
open or shorted wire. You should be able to read and
understand a wiring diagram.
Use of Circuit Testing Tools - You should know how
to use a test light and how to bypass components to
test circuits using fused jumper wires. You should be
familiar with a digital multimeter. You should be able
to measure voltage, resistance, and current, and be
familiar with the controls and how to use them correctly.
Basic Hydraulic System
Each solenoid valve consists of one inlet valve and
one outlet valve in order to become the channel.
DESCRIPTION AND OPERATION
The inlet valve and the outlet valve close/open by the
electrical signal and control the hydraulic pressure as
increase, decrease and hold.
ABS System Components
The ABS 5.3 Antilock Braking System (ABS) consists
of a conventional hydraulic brake system plus antilock
components. The conventional brake system includes
a vacuum booster, master cylinder, front disc brakes,
rear disc brakes, interconnecting hydraulic brake pipes
and hoses, brake fluid level switch and the BRAKE
indicator.
The ABS components include a hydraulic unit, an
electronic brake control module (EBCM), two system
fuses, four wheel speed sensors (one at each wheel),
interconnecting wiring, the ABS indicator, the EBD
indicator and the TCS indicator, See "ABS Component
Locator" in this section for the general layout of this
system.
The basic hydraulic unit configuration consists of
hydraulic check valves, two solenoid valves for each
wheel, a hydraulic pump, and two accumulators. The
hydraulic unit controls hydraulic pressure to the front
calipers and rear calipers by modulating hydraulic
pressure to prevent wheel lockup.
Units equipped with TCS add two more valves for each
drive wheel for the purpose of applying the brake to a
wheel that is slipping. This is done with pressure from
the hydraulic pump in the unit. There is also a TCS
indicator lamp on the instrument panel to alert the driver
to the fact that the TCS system is active. The
components identified in the drawing are those added
to the basic ABS 5.3 system to provide traction control.
Nothing the hydraulic unit or the EBCM is serviceable.
In the event of any failure, the entire ABS unit with
attached EBCM must be replaced. For more information,
refer to "Base Braking Mode" and "Antilock Braking
Mode" in the section.
YAD4E010
SSANGYONG Y200
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