2003 DAEWOO MATIZ lock

4A –4 HYDRAULIC BRAKES
DAEWOO M-150 BL2
DIAGNOSITIC INFORMATION AND PROCEDURES
BRAKE SYSTEM TESTING
(Left–Hand Drive Shown, Right–Hand
Drive Similar)
Brakes should be tested on a dry, clean, reasonably
smooth and level roadway. A true test of brake perfor-
mance cannot be made if the roadway is wet, greasy, or
covered with loose dirt whereby all tires do not grip the
road equally. Testing will also be adversely affected if the
roadway is crowned so as to throw the weight so roughly
that the wheels tend to bounce.
Test the brakes at different vehicle speeds with both light
and heavy pedal pressure; however, avoid locking the
brakes and sliding the tires. Locked brakes and sliding
tires do not indicate brake efficiency since heavily
braked, but turning, wheels will stop the vehicle in less
distance than locked brakes. More tire-to-road friction is
present with a heavily braked, turning tire than with a
sliding tire.
Because of the high deceleration capability, a firmer
pedal may be felt at higher deceleration levels.
There are three major external conditions that affect
brake performance:

Tires having unequal contact and grip of the road will
cause unequal braking. Tires must be equally in-
flated, and the tread pattern of the right and the left
tires must be approximately equal.

Unequal loading of the vehicle can affect the brake
performance since the most heavily loaded wheels
require more braking power, and thus more braking
effort, than the others.

Misalignment of the wheels, particularly conditions of
excessive camber and caster, will cause the brakes
to pull to one side.
To check for brake fluid leaks, hold constant foot pres-
sure on the pedal with the engine running at idle and the
shift lever in NEUTRAL. If the pedal gradually falls away
with the constant pressure, the hydraulic system may be
leaking. Perform a visual check to confirm any sus-
pected leaks.
Check the master cylinder fluid level. While a slight drop
in the reservoir level results from normal lining wear, an
abnormally low level indicates a leak in the system. The
hydraulic system may be leaking either internally or ex-
ternally. Refer to the procedure below to check the mas-
ter cylinder. Also, the system may appear to pass this
test while still having a slight leak. If the fluid level is nor-
mal, check the vacuum booster pushrod length. If an in-
correct pushrod length is found, adjust or replace the
rod.Check the master cylinder using the following proce-
dure:

Check for a cracked master cylinder casting or brake
fluid leaking around the master cylinder. Leaks are in-
dicated only if there is at least one drop of fluid. A
damp condition is not abnormal.

Check for a binding pedal linkage and for an incorrect
pushrod length. If both of these parts are in satisfac-
tory condition, disassemble the master cylinder and
check for an elongated or swollen primary cylinder or
piston seals. If swollen seals are found, substandard
or contaminated brake fluid should be suspected. If
contaminated brake fluid is found, all the components
should be disassembled and cleaned, and all the rub-
ber components should be replaced. All of the pipes
must also be flushed.
Improper brake fluid, or mineral oil or water in the fluid,
may cause the brake fluid to boil or cause deterioration
of the rubber components. If the primary piston cups in
the master cylinder are swollen, then the rubber parts
have deteriorated. This deterioration may also be evi-
denced by swollen wheel cylinder piston seals on the
drum brake wheels.
If rubber deterioration is evident, disassemble all the hy-
draulic parts and wash the parts with alcohol. Dry these
parts with compressed air before reassembly to keep al-
cohol out of the system. Replace all the rubber parts in
the system, including the hoses. Also, when working on
the brake mechanisms, check for fluid on the linings. If
excessive fluid is found, replace the linings.
If the master cylinder piston seals are in satisfactory
condition, check for leaks or excessive heat conditions.
If these conditions are not found, drain the fluid, flush the
master cylinder with brake fluid, refill the master cylin-
der, and bleed the system. Refer to “Manual Bleeding
the Brakes” in this section.
BRAKE HOSE INSPECTION
The hydraulic brake hoses should be inspected at least
twice a year. The brake hose assembly should be
checked for road hazard damage, cracks, chafing of the
outer cover, and for leaks or blisters. Inspect the hoses
for proper routing and mounting. A brake hose that rubs
on a suspension component will wear and eventually
fail. A light and a mirror may be needed for an adequate
inspection. If any of the above conditions are observed
on the brake hose, adjust or replace the hose as neces-
sary.

4B –2 MASTER CYLINDER
DAEWOO M-150 BL2
DESCRIPTION AND OPERATION
MASTER CYLINDER
The master cylinder is designed for use in a direct–split
system. Front right brake and rear left brake are served
by the primary piston. Front left brake and rear right
brake are served by the secondary piston.
The master cylinder incorporates the functions of the
standard dual master cylinder, plus a low fluid level indi-
cator and the proportioning valve in the non–antilock
braking system.
The proportioning valves limit the outlet pressure to the
rear brakes after a predetermined master cylinder has
been reached.
Important:

Replace all the components included in the repair kits
used to service this master cylinder.

Lubricate rubber parts with clean brake fluid to ease
assembly.

Do not use lubricated shop air on brake parts, as this
may damage rubber components.

If any hydraulic component is removed or discon-
nected, it may be necessary to bleed all or part of the
brake system.
The torque values specified are for dry, unlubricated
fasteners.

Perform all service operations on a clean bench, free
from all traces of mineral oil.
PROPORTIONING VALVE
The proportioning valve limits the outlet pressure to the
rear brakes on the non-ABS after a predetermined mas-
ter cylinder pressure has been reached. This is used
when less rear apply force is needed to obtain optimum
braking and is usually found on disc/drum brake configu-
rations. On ABS-equipped vehicles, refer to Section 4F,
Antilock Brake System.
FLUID LEVEL SENSOR
Fluid level sensor is attached at the brake fluid reservoir.
This sensor will activate the BRAKE light if a low fluid
level condition is detected. Once the fluid level is cor-
rected, the BRAKE light will go out.

4B –6 MASTER CYLINDER
DAEWOO M-150 BL2
Notice: Brake fluid may damage paintwork, if spillage
onto paintwork, wash with cold water immediately.
MAB4B004
Installation procedure
1. Install the proportioning valve (1).
Tighten
Tighten the proportioning valve to 22 Nm (16 lb-ft).
2. Install the brake pipe fitting (2).
Tighten
Tighten the brake pipe fitting–to–proportioning valve
to 16 Nm (12 lb-ft).
3. Bleed the brake system. Refer to Section 4A, Hy-
draulic Brakes.
D107A504
BRAKE FLUID LEVEL SWITCH
Removal procedure
1. Remove the vacuum hose from the power booster.
Refer to Section 4C, Power Booster.
2. Remove the brake fluid level switch.

Remove the brake fluid level switch locking system
by the flathead screwdriver (1).
D107A505

Disconnect the electrical connector (2).

DAEWOO M-150 BL2
SECTION 4F
ANTILOCK BRAKE SYSTEM
CAUTION: Disconnect the negative battery cable before removing or installing any electrical unit or when a
tool or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable
will help prevent personal injury and damage to the vehicle. The ignition must also be in B unless otherwise
noted.
CAUTION: Don’t diagnosis the Antilock Brake System (ABS) under the vehicle moving status. Because the
ABS function will be stopped.
TABLE OF CONTENTS
Description and Operation 4F-3. . . . . . . . . . . . . . . . . .
ABS System Components 4F-3. . . . . . . . . . . . . . . . . .
Hydraulic Unit 4F-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EBCM (Electronic Brake Control Module) 4F-4. . . . .
Wheel Speed Sensors and Rings 4F-5. . . . . . . . . . . .
Electronic Brake Distribution 4F-5. . . . . . . . . . . . . . . .
Indicator 4F-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EBCM Connector 4F-6. . . . . . . . . . . . . . . . . . . . . . . . . .
Hydraulic Fluid Flow Diagrams 4F-7. . . . . . . . . . . . . .
Normal Braking Mode 4F-7. . . . . . . . . . . . . . . . . . . .
Isolation Mode (Pressure Maintain) 4F-8. . . . . . . .
Dump Mode (Pressure Decrease) 4F-9. . . . . . . . .
Reapply Mode (Pressure Increase) 4F-10. . . . . . .
Proportioning Function 4F-11. . . . . . . . . . . . . . . . . .
Visual Identification 4F-12. . . . . . . . . . . . . . . . . . . . . . .
EBCM Connector Face View 4F-12. . . . . . . . . . . . . . .
Component Locator 4F-13. . . . . . . . . . . . . . . . . . . . . . .
ABS 4F-13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Information and Procedures 4F-16. . . .
DTC 0354 Left Front Wheel Speed Sensor
Circuit Open or Shorted 4F-16. . . . . . . . . . . . . . . . .
DTC 0355 Left Front Wheel Speed Sensor
Poor Air Gap or Missing Tooth Ring 4F-20. . . . . . .
DTC 0356 Left Front Wheel Speed Sensor
Circuit Intermittent Shorted 4F-22. . . . . . . . . . . . . .
DTC 0404 Right Front Wheel Speed Sensor
Circuit Open or Shorted 4F-24. . . . . . . . . . . . . . . . .
DTC 0405 Right Front Wheel Speed Sensor
Poor Air Gap or Missing Tooth Ring 4F-28. . . . . . .
DTC 0406 Right Front Wheel Speed Sensor
Circuit Intermittent Shorted 4F-30. . . . . . . . . . . . . .
DTC 0454 Left Rear Wheel Speed Sensor
Circuit Open or Shorted 4F-32. . . . . . . . . . . . . . . . .
DTC 0455 Left Rear Wheel Speed Sensor
Poor Air Gap or Missing Tooth Ring 4F-36. . . . . . . DTC 0456 Left Rear Wheel Speed Sensor
Circuit Intermittent Shorted 4F-38. . . . . . . . . . . . . .
DTC 0504 Right Rear Wheel Speed Sensor
Circuit Open or Shorted 4F-42. . . . . . . . . . . . . . . . .
DTC 0505 Right Rear Wheel Speed Sensor
Poor Air Gap or Missing Tooth Ring 4F-46. . . . . . .
DTC 0506 Right Rear Wheel Speed Sensor
Circuit Intermittent Shorted 4F-48. . . . . . . . . . . . . .
DTC 0601 Left Front Dump Shorted or
Driver Open 4F-52. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC 0602 Left Front Dump Open or
Driver Shorted 4F-54. . . . . . . . . . . . . . . . . . . . . . . . .
DTC 0651 Left Front Isolation Shorted or
Driver Open 4F-56. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC 0652 Left Front Isolation Open or
Driver Shorted 4F-58. . . . . . . . . . . . . . . . . . . . . . . . .
DTC 0701 Right Front Dump Shorted or
Driver Open 4F-60. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC 0702 Right Front Dump Open or
Driver Shorted 4F-62. . . . . . . . . . . . . . . . . . . . . . . . .
DTC 0751 Right Front Isolation Shorted or
Driver Open 4F-64. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC 0752 Right Front Isolation Open or
Driver Shorted 4F-66. . . . . . . . . . . . . . . . . . . . . . . . .
DTC 0801 Left Rear Dump Shorted or
Driver Open 4F-68. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC 0802 Left Rear Dump Open or
Driver Shorted 4F-70. . . . . . . . . . . . . . . . . . . . . . . . .
DTC 0851 Left Rear Isolation Shorted or
Driver Open 4F-72. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC 0852 Left Rear Isolation Open or
Driver Shorted 4F-74. . . . . . . . . . . . . . . . . . . . . . . . .
DTC 0901 Right Rear Dump Shorted or
Driver Open 4F-76. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC 0902 Right Rear Dump Open or
Driver Shorted 4F-78. . . . . . . . . . . . . . . . . . . . . . . . .

4F – 2 ANTILOCK BRAKE SYSTEM
DAEWOO M-150 BL2
DTC 0951 Right Rear Isolation Shorted or
Driver Open 4F-80. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC 0952 Right Rear Isolation Open or
Driver Shorted 4F-82. . . . . . . . . . . . . . . . . . . . . . . . .
DTC 1102 Return Pump Motor Circuit Open 4F-84. .
DTC 1103 Return Pump Motor Relay Fault 4F-86. . .
DTC 1104 Return Pump Motor Circuit
Shorted 4F-88. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC 1211 EBCM Main Relay Shorted 4F-90. . . . . . .
DTC 1212 EBCM Main Relay Open 4F-92. . . . . . . . .
DTC 1213 EBCM Main Relay Fault 4F-94. . . . . . . . .
DTC 1610 Stoplamp Switch Circuit Open 4F-96. . . .
DTC 2321 ABS (Amber) Indicator Shorted
to Battery 4F-100. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC 2322 ABS (Amber) Indicator Shorted
to Ground 4F-104. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC 2458 Wheel Speed Sensor
Intermittent Error 4F-107. . . . . . . . . . . . . . . . . . . . . .
DTC 2459 Wheel Speed Sensor Excessive
Wheel Speed Variation 4F-108. . . . . . . . . . . . . . . . .
DTC 2520 EBCM Internal Fault 4F-110. . . . . . . . . . .
DTC 5501 Vehicle Inhibit Code 4F-112. . . . . . . . . . . .
DTC 5502 Isolation Valve Time–Out 4F-114. . . . . . .
DTC 5503 CPU Loop Time Error 4F-115. . . . . . . . . .
DTC 5504 Excessive Dump Valve Time 4F-116. . . .
DTC 5560 Inoperative External Watch–Dog 4F-117.
DTC 5610 RAM/ROM Error 8 Bit 4F-118. . . . . . . . . .
DTC 5630 ROM Error 16 Bit 4F-119. . . . . . . . . . . . . . DTC 5640 RAM Error 16 Bit 4F-120. . . . . . . . . . . . . .
DTC 8001 Battery High Voltage Fault
(More Than 16V) 4F-122. . . . . . . . . . . . . . . . . . . . . .
DTC 8002 Battery Low Voltage Fault
(Less Than 9V) 4F-124. . . . . . . . . . . . . . . . . . . . . . .
DTC 8003 Battery Low Voltage Fault
(Less Than 9.5V) 4F-126. . . . . . . . . . . . . . . . . . . . . .
Repair Instructions 4F-128. . . . . . . . . . . . . . . . . . . . . . .
On-Vehicle Service 4F-128. . . . . . . . . . . . . . . . . . . . . . . .
Service Precautions 4F-128. . . . . . . . . . . . . . . . . . . . .
Bleeding System 4F-128. . . . . . . . . . . . . . . . . . . . . . . .
Front Wheel Speed Sensor 4F-129. . . . . . . . . . . . . . .
Rear Wheel Speed Sensor 4F-130. . . . . . . . . . . . . . .
Front Wheel Speed Ring 4F-131. . . . . . . . . . . . . . . . .
Rear Wheel Speed Ring 4F-131. . . . . . . . . . . . . . . . . .
Hydraulic Modulator and Upper/Lower
Mounting Bracket 4F-132. . . . . . . . . . . . . . . . . . . . . .
EBCM (Electronic Brake Control Module) 4F-134. . .
Specifications 4F-136. . . . . . . . . . . . . . . . . . . . . . . . . . .
General Specifications 4F-136. . . . . . . . . . . . . . . . . . .
Fastener Tightening Specifications 4F-136. . . . . . . . .
Special Tools and Equipment 4F-136. . . . . . . . . . . . .
Special Tools Table 4F-136. . . . . . . . . . . . . . . . . . . . . .
Schematic and Routing Diagrams 4F-137. . . . . . . . .
ABS Circuit 4F-137. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ABS Block Diagram 4F-140. . . . . . . . . . . . . . . . . . . . . .

ANTILOCK BRAKE SYSTEM 4F–3
DAEWOO M-150 BL2
DESCRIPTION AND OPERATION
ABS SYSTEM COMPONENTS
The Antilock Braking System (ABS) consists of a con-
ventional hydraulic brake system plus antilock compo-
nents. The conventional brake system includes a
vacuum booster, master cylinder, front disc brakes, rear
drum brakes, interconnecting hydraulic brake pipes and
hoses, brake fluid level sensor and the BRAKE indicator.
The ABS components include a hydraulic unit, an elec-
tronic brake control module (EBCM), two system fuses,
four wheel speed sensors (one at each wheel), intercon-
necting wiring, the ABS indicator, and the rear drum
brake. See “ABS Component Locator” in this section for
the general layout of this system.
HYDRAULIC UNIT
The hydraulic unit with the attached EBCM is located
between the surge tank and the fire wall on the right side
of the vehicle. The basic hydraulic unit configuration
consists of return pump motor, return pump, four isola-
tion valves, four dump valves, two Low Pressure Accu-
mulators (LPA), two High Pressure Attenuators (HPA).
The hydraulic unit controls hydraulic pressure to the
front calipers and rear wheel cylinders by modulating hy-
draulic pressure to prevent wheel lockup.
Isolation valve
The isolation valve is placed in the brake fluid path from
the master cylinder to the relevant brake caliper and al-
lows free flow as commanded by the driver during nor-
mal braking and reapply phases.
In the isolation phase the coil moves the armature down,
which closes the normally open isolation orifice and pre-
vents any further increase of pressure in the brake. The
valve also remains closed during the dump phase.
The lip seal provides a one way return path for brake
fluid to flow through in:
1. Foot off pedal during isolation.
2. Residual LPA fluid.
D107E002
Dump Valve
The dump valve creates a flow path from the isolation
cartridge (brake side) to the low pressure accumulator
(LPA). The valve keeps this path permanently closed ex-
cept during the dump phase in the ABS mode. On ac-
tivation (dump phase), the coil moves up the armature
which opens the normally closed dump orifice and allow
to drain the pressure in the brake line with the brake fluid
flowing into the LPA.
The lip seal provides a return path for residual brake
fluid in the LPA.
D107E003
Low Pressure Accumulator (LPA)
LPA provides a variable chamber for brake fluid to be
quickly pushed in through the dump valve at the begin-
ning of a departure. This chamber then acts as a reser-
voir which buffers the pump.
D107E004
High Pressure Attenuator (HPA)
The HPA is in between the pump and the ISO valve
(master cylinder side) and uses the bulk mode of the
contained plastic damper and orifice size to dump out
the pressure oscillations from the pump to reduce the

4F–4 ANTILOCK BRAKE SYSTEM
DAEWOO M-150 BL2
feed back to the master cylinder and brake pedal.
D107E005
Return Pump Motor
The motor drives two pump elements through the ec-
centric wheel on its shaft.
Return Pump
Description: Each pump element consists of a fixed
displacement piston driven by an eccentric on the end of
the eccentric motor. It has two check valves (inlet and
outlet) and is fed with fluid by the low pressure accumu-
lator.
Operation:
Compression stroke: the pump is filled via the inlet ball
seat, then the motor eccentric rotates moving the piston
to displace the fluid. After the pressure build-up closes
the inlet valve the piston displacement increases the
pressure until the outlet ball opens. The outlet pressure
will continue to increase for the rest of the piston stroke.
Return Stroke: The piston retracts, forced by its spring,
as the motor eccentric returns to its low end position.
The pressure at the inlet side of the outlet ball then de-
creases due to the displaced volume and the pressure
difference across this ball holds it closed.
The pressure at the outlet side of the inlet ball seat,
which is set to open at a certain pressure level also de-
creases until this valve opens. With the outlet ball
closed, the pump is filled with additional fluid from the
low pressure accumulator.
The pressure will continue until a stall point is reached
and compression of the piston cannot generate enough
differential pressure anymore to open the outlet ball
seat.
D17E006A
Return Pump
Return Pump
Motor(0.12~0.16 in.)
EBCM (ELECTRONIC BRAKE
CONTROL MODULE)
Notice: There is no serviceable. The EBCM must be re-
placed as an assembly.
The EBCM is attached to the hydraulic unit in the engine
compartment. The controlling element of ABS is a mi-
croprocessor-based EBCM. Inputs to the system in-
clude the four wheel speed sensors, the stoplamp
switch, the ignition switch, and the unswitched battery
voltage. There is an output to a bi-directional serial data
link, located in pin M of the assembly line diagnostic link
(ALDL), for service diagnostic tools and assembly plat
testing.
The EBCM monitors the speed of each wheel. If any
wheel begins to approach lockup and the brake switch is
closed (brake pedal depressed), the EBCM controls the
dump valve to reduce brake pressure to the wheel ap-
proaching lockup. Once the wheel regains traction,
brake pressure is increased until the wheel again begins
to approach lockup. The cycle repeats until either the
vehicle comes to a stop, the brake pedal is released or
no wheels approach lockup.
Additionally, the EBCM monitors itself, each input (ex-
cept the serial data link), and each output for proper op-
eration. If it detects any system malfunction, the EBCM
will store a DTC in nonvolatile memory (DTCs will not
disappear if the battery is disconnected).

ANTILOCK BRAKE SYSTEM 4F–5
DAEWOO M-150 BL2
D107E001
WHEEL SPEED SENSORS AND
RINGS
Front wheel speed sensors are installed to the front
knuckle and rear wheel speed sensors are installed to
the backing plate.
Wheel speed sensors are no serviceable. And the air
cap is not adjusted. Front wheel speed sensor ring is
pressed onto the drive axle shaft. Each ring contains 40
equally spaced teeth. Exercise care during service pro-
cedures to avoid prying or contacting this ring. Exces-
sive contact may cause damage to one or more teeth.
Rear wheel speed sensor rings are incorporated into the
hub drum.
D107E007
D107E008
ELECTRONIC BRAKE DISTRIBUTION
ABS features an enhanced algorithm which includes
control of the brake force distribution between the front
and rear axles. This is called Electronic Brake Distribu-
tion or Dynamic Rear Proportioning valve. In an unladen
car condition the brake efficiency is comparable to the
conventional system but for a fully loaden vehicle the ef-
ficiency of the Dynamic Rear Proportioning System is
higher due to the better use of rear axle braking capabili-
ty.
No indication is given to the driver when Dynamic Rear
Proportioning is activated. Also, DRP remains active
even in such cases where the anti-lock function of the
ABS is disabled.
D17E009A
Critical Brake Points
Ideal Distribution
Fully Laden Vehicle
Ideal Distribution
Lightly Loaded
Vehicle
Advanced Distribution with ABS
Regular Distribution without Dynamic
Rear Proportioning
Relative Front Brake Force
INDICATOR
It illuminates for four seconds immediately after the igni-
tion has been turned on to show that the anti-lock sys-
tem self-test is being carried out. If the light does not go
off after this time it means that there may be a problem
and ABS operation is not available.
If any malfunction or error, including an unplugged
EBCM connector, is detected during vehicle operation,
the light will come on, warning the driver that the ABS is
not operative and brake operation is in conventional,
non-ABS mode.
D17E010A