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09-174850-01
Brake Fluid ▶
Brake Fluid Type ▶ 1. Color
Ligh gold (New oil) → Brown → Black -
2. Service Interval/Type
Change: every 2 years, Type: DOT4
The water in the brake fluid has an adverse effect to the brake system. If the fluid contains
around 3% of water, the boiling point of the brake fluid goes down by 25%. It will cause the vapor
lock frequently.
Water content in fluid: around 3% after 18 months, around 7~10% after few years
The water ib fluid makes the corrosion in the brake lines, deforms and deteriorates the rubber
components, brake calipers and pistons. -
DOT4: Brake fluid for premium vehicle. Lower water absorbing rate AND higher boiling point than
DOT3
Brake Fluid Level Check ▶
The brake fluid level should be between "MAX"
and "MIN" on the reservoir. If it is below "MIN"
mark, check for oil leaks and refill the reservoir
with the specified fluid.
Page 581 of 751
09-32
4. HYDRAULIC CIRCUIT
Brake booster
Brake fluid reservoir and master cylinder
Front disc brake and caliper 1.
2.
3.HECU (Hydraulic & Electric Control Unit)
Rear disc brake and caliper 4.
5.
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10-12
2) EBD (Electronic Brake-force Distribution) Warning Lamp
EBD warning lamps (brake warning lamp and ABS warning lamp) come on when the system performs
the self diagnosis and when it detects the malfunction of EBD system. However, the brake warning lamp
comes on regardless of EBD system when the parking brake is applied.
EBD warning lamp ON:
When turning the ignition switch to ON position, ABS warning lamp and the brake warning lamp
comes on for 3 seconds for self diagnosis and goes off if the system is OK (initialization mode).
When applying the parking brake, the brake warning lamp comes on.
When the brake fluid is not sufficient, the brake warning lamp comes on.
When disengaging the connector, the warning lamp comes on.
When the system is defective, ABS warning lamp and the brake warning lamp come on
simultaneously. A.
B.
C.
D.
E.
When the solenoid valve is defective
When one or more wheel sensors are defective
When ABS HECU is defective
When the voltage is abnormal
When valve relay is defective a.
b.
c.
d.
e.
When the communication between warning lamp CAN modules in meter cluster is failed, the
warning lamp comes on. F.
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11-14
2) EBD (Electronic Brake-force Distribution) Warning Lamp (Brake
Warning Lamp)
EBD warning lamp when the system perform the self diagnosis and when it detects the malfunction of
EBD system. However, the brake warning lamp comes on regardless of EBD when the parking brake is
applied.
EBD warning lamp ON:
When turning the ignition switch to ON position, ABS warning lamp and the brake warning lamp
comes on for 3 seconds for self diagnosis and goes off if the system is OK (initialization mode).
When applying the parking brake, the brake warning lamp comes on.
When the brake fluid is not sufficient, the brake warning lamp comes on.
When disengaging the connector, the warning lamp comes on.
When the system is defective, ABS warning lamp and the brake warning lamp come on
simultaneously. 1.
2.
3.
4.
5.
When the solenoid valve is defective
When one or more wheel sensors are defective
When ABS HECU is defective
When the voltage is abnormal
When valve relay is defective a.
b.
c.
d.
e.
When the communication between warning lamp CAN module in meter cluster, the warning
lamp comes on. 6.
3) ESP OFF Indicator
ESP OFF indicator ON:
When turning the ignition switch to ON position, ESP warning lamp comes on for 3 seconds for self
diagnosis and goes off if the system is OK (initialization mode).
When the ESP OFF switch is pressed to turn off ESP function, ESP OFF indicator comes on. 1.
2.
4) ESP Warning Lamp
ESP warning lamp ON:
When turning the ignition switch to ON position, ESP warning lamp comes on for 3 seconds for
self diagnosis and goes off if the system is OK (initialization mode).
When the system is defective, the warning lamp comes on.
When the ESP function is activated, ESP warning lamp blinks with the interval of 2 Hz.
When the communication between warning lamp CAN module in meter cluster, the warning lamp
comes on. 1.
2.
3.
4.
5.
5) ESP OFF Switch
If ESP OFF switch is pressed, ESP function is deactivated and the ESP OFF indicator in the instrument
cluster comes on.
To resume the ESP function, press the switch again. At this time, ESP OFF indicator goes out.
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11-194890-10
4) HBA (Hydraulic Brake Assist System)
(1) Purpose
HBA (Hydraulic Brake Assist) system helps in an emergency braking situation when the driver applies
the brake fast, but not with sufficient pressure, which leads to dangerously long braking distance. ECU
recognizes the attempt at full braking and transmits the signal calling for full brake pressure from the
hydraulic booster. An inexperienced, elderly or physically weak driver may suffer from the accident by not
fully pressing the brake pedal when hard braking is required under emergency. The HBA System
increases the braking force under urgent situations to enhance the inputted braking force from the driver.
Based on the fact that some drivers depress the brake pedal too soft even under when hard braking is
necessary, the HECU system is a safety supplementary system that builds high braking force during
initial braking according to pressure value of the brake pressure sensor and the pressure changes of the
pressure sensor intervals. When the system is designed to apply high braking force when brake pedal is
depressed softly by an elderly or physically weak driver, the vehicle will make abrupt stopping under
normal braking situation due to high braking pressure at each wheels.
(2) Operation
The brake pressure value and the changed value of the pressure sensor are the conditions in which the
HBA System operates. There are 2 pressure sensors under the master cylinder. When the ESP ECU
system determines that emergency braking is present, the pump operates, the brake fluid in the master
cylinder is sent to the pump and the braking pressure is delivered to the wheels via the inlet valves . If the
drive depress the brake pedal slowly, the pressure change is not high. In this case, only the conventional
brake system with booster is activated.
(3) Operating conditions
Sensor pressure: over 40 bar
Pressure changes: over 850 bar/sec
Vehicle speed: over 30 km/h -
-
-
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11-234890-10
1) Idling and Normal Braking Condition
In this position, the separation valve and the inlet valve are open (normal open), the electrically operated
shuttle valve and the outlet valve are closed.
When the brake is applied under these conditions, the brake fluid will be sent to each wheel via the
separation valve and inlet valve.
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12-134610-01
4. TROUBLESHOOTING
Problem Possible Cause Action
Movements of steering
feels heavyIrregular wear or binding of steering ball joint due
to lack of lubrication or foreign material insertionLubricate or replace
Damaged or defective steering gear Replace the steering
gear assembly
Incorrect steering pinion preload Adjust
Defective steering shaft joint Replace
leakage of steering fluid Repair or replace
Insufficient steering fluid or air insertion Fill up fluid or bleed air
Defective steering oil pump Replace
Damaged or loosened pump drive belt Adjust or replace
Clogging of fluid line Repair or replace
Damaged wheel or tire Repair or replace
Defective suspension Repair or replace
Steering wheel pulls to
one sideDamaged steering linkage Replace
Damaged wheel or tire Repair or replace
Defective suspension Repair or replace
Defective brake system Repair or replace
Excessive free play of
steering wheelWorn steering gear Replace the steering
gear assembly
Worn or damaged steering ball joint Replace
Looseness of steering gear box Retighten
Poor returning of
steering wheelBroken or binding of steering ball joint Replace
Improper correct steering pinion preload Replace the steering
gear assembly
Damaged wheel or tire Repair or replace
Defective suspension Repair or replace