ABS DAEWOO NUBIRA 2004 Service Owners Manual

1F – 624IENGINE CONTROLS
DAEWOO V–121 BL4
Because of the constant measuring and adjusting of the
air/fuel ratio, the fuel injection system is called a ”closed
loop” system.
The ECM uses voltage inputs from several sensors to de-
termine how much fuel to provide to the engine. The fuel
is delivered under one of several conditions, called
”modes.”
Starting Mode
When the ignition is turned ON, the ECM turns the fuel
pump relay on for two seconds. The fuel pump then builds
fuel pressure. The ECM also checks the Engine Coolant
Temperature (ECT) sensor and the Throttle Position (TP)
sensor and determines the proper air/fuel ratio for starting
the engine. This ranges from 1.5 to 1 at –97 °F (–36 °C)
coolant temperature to 14.7 to 1 at 201 °F (94 °C) coolant
temperature. The ECM controls the amount of fuel deliv-
ered in the starting mode by changing how long the fuel in-
jector is turned on and off. This is done by ”pulsing” the fuel
injectors for very short times.
Clear Flood Mode
If the engine floods with excessive fuel, it may be cleared
by pushing the accelerator pedal down all the way. The
ECM will then completely turn off the fuel by eliminating
any fuel injector signal. The ECM holds this injector rate
as long as the throttle stays wide open and the engine is
below approximately 400. If the throttle position becomes
less than approximately 80 percent, the ECM returns to
the starting mode.
Run Mode
The run mode has two conditions called ”open loop” and
”closed loop.”
Open Loop
When the engine is first started and it is above 400 rpm,
the system goes into ”open loop” operation. In ”open loop,”
the ECM ignores the signal from the HO2S and calculates
the air/fuel ratio based on inputs from the ECT sensor and
the MAP sensor. The sensor stays in ”open loop” until the
following conditions are met:
S The HO2S sensor has a varying voltage output,
showing that it is hot enough to operate properly.
S The ECT sensor is above a specified temperature.
S A specific amount of time has elapsed after starting
the engine.
Closed Loop
The specific values for the above conditions vary with dif-
ferent engines and are stored in the Electronically Eras-
able Programmable Read–Only Memory (EEPROM).
When these conditions are met, the system goes into
”closed loop” operation. In ”closed loop,” the ECM calcu-
lates the air/fuel ratio (fuel injector on–time) based on the
signal from the oxygen sensor. This allows the air/fuel ratio
to stay very close to 14.7 to 1.Acceleration Mode
The ECM responds to rapid changes in throttle position
and airflow and provides extra fuel.
Deceleration Mode
The ECM responds to changes in throttle position and air-
flow and reduces the amount of fuel. When deceleration
is very fast, the ECM can cut off fuel completely for short
periods of time.
Battery Voltage Correction Mode
When battery voltage is low, the ECM can compensate for
a weak spark delivered by the ignition module by using the
following methods:
S Increasing the fuel injector pulse width.
S Increasing the idle speed rpm.
S Increasing the ignition dwell time.
Fuel Cut–Off Mode
No fuel is delivered by the fuel injectors when the ignition
is OFF. This prevents dieseling or engine run–on. Also, the
fuel is not delivered if there are no reference pulses re-
ceived from the central power supply. This prevents flood-
ing.
EVAPORATIVE EMISSION CONTROL
SYSTEM OPERATION
The basic Evaporative (EVAP) Emission control system
used is the charcoal canister storage method. This meth-
od transfers fuel vapor from the fuel tank to an activated
carbon (charcoal) storage device (canister) to hold the va-
pors when the vehicle is not operating. When the engine
is running, the fuel vapor is purged from the carbon ele-
ment by intake airflow and consumed in the normal com-
bustion process.
Gasoline vapors from the fuel tank flow into the tube la-
beled TANK. These vapors are absorbed into the carbon.
The canister is purged by the engine control module
(ECM) when the engine has been running for a specified
amount of time. Air is drawn into the canister and mixed
with the vapor. This mixture is then drawn into the intake
manifold.
The ECM supplies a ground to energize the EVAP emis-
sion canister purge solenoid valve. This valve is Pulse
Width Modulated (PWM) or turned on and off several
times a second. The EVAP emission canister purge PWM
duty cycle varies according to operating conditions deter-
mined by mass airflow, fuel trim, and intake air tempera-
ture.
Poor idle, stalling, and poor driveability can be caused by
the following conditions:
S An inoperative EVAP emission canister purge sole-
noid valve.
S A damaged canister.
S Hoses that are split, cracked, or not connected to
the proper tubes.

1F – 626IENGINE CONTROLS
DAEWOO V–121 BL4
EXHAUST GAS RECIRCULATION
VA LV E
The Exhaust Gas Recirculation (EGR) system is used on
engines equipped with an automatic transaxle to lower
NOx (oxides of nitrogen) emission levels caused by high
combustion temperature. The EGR valve is controlled by
the engine control module (ECM). The EGR valve feeds
small amounts of exhaust gas into the intake manifold to
decrease combustion temperature. The amount of ex-
haust gas recirculated is controlled by variations in vacu-
um and exhaust back pressure. If too much exhaust gas
enters, combustion will not take place. For this reason,
very little exhaust gas is allowed to pass through the valve,
especially at idle.
The EGR valve is usually open under the following condi-
tions:
S Warm engine operation.
S Above idle speed.
Results of Incorrect Operation
Too much EGR flow tends to weaken combustion, causing
the engine to run roughly or to stop. With too much EGR
flow at idle, cruise, or cold operation, any of the following
conditions may occur:
S The engine stops after a cold start.
S The engine stops at idle after deceleration.
S The vehicle surges during cruise.
S Rough idle.
If the EGR valve stays open all the time, the engine may
not idle. Too little or no EGR flow allows combustion tem-
peratures to get too high during acceleration and load con-
ditions. This could cause the following conditions:
S Spark knock (detonation)
S Engine overheating
S Emission test failure
INTAKE AIR TEMPERATURE
SENSOR
The Intake Air Temperature (IAT) sensor is a thermistor,
a resistor which changes value based on the temperature
of the air entering the engine. Low temperature produces
a high resistance (4,500 ohms at –40°F [–40°C]), while
high temperature causes a low resistance (70 ohms at
266°F [130°C]).
The engine control module (ECM) provides 5 volts to the
IAT sensor through a resistor in the ECM and measures
the change in voltage to determine the IAT. The voltage will
be high when the manifold air is cold and low when the air
is hot. The ECM knows the intake IAT by measuring the
voltage.
The IAT sensor is also used to control spark timing when
the manifold air is cold.
A failure in the IAT sensor circuit sets a diagnostic trouble
code P0112 or P0113.
IDLE AIR CONTROL VALVE
Notice : Do not attempt to remove the protective cap to
readjust the stop screw. Misadjustment may result in dam-
age to the Idle Air Control (IAC) valve or to the throttle
body.
The IAC valve is mounted on the throttle body where it
controls the engine idle speed under the command of the
engine control module (ECM). The ECM sends voltage
pulses to the IAC valve motor windings, causing the IAC
valve pintle to move in or out a given distance (a step or
count) for each pulse. The pintle movement controls the
airflow around the throttle valves which, in turn, control the
engine idle speed.
The desired idle speeds for all engine operating conditions
are programmed into the calibration of the ECM. These
programmed engine speeds are based on the coolant
temperature, the park/neutral position switch status, the
vehicle speed, the battery voltage, and the A/C system
pressure (if equipped).
The ECM ”learns” the proper IAC valve positions to
achieve warm, stabilized idle speeds (rpm) desired for the
various conditions (park/neutral or drive, A/C on or off, if
equipped). This information is stored in ECM ”keep alive”
memories. Information is retained after the ignition is
turned OFF. All other IAC valve positioning is calculated
based on these memory values. As a result, engine varia-
tions due to wear and variations in the minimum throttle
valve position (within limits) do not affect engine idle
speeds. This system provides correct idle control under all
conditions. This also means that disconnecting power to
the ECM can result in incorrect idle control or the necessity
to partially press the accelerator when starting until the
ECM relearns idle control.
Engine idle speed is a function of total airflow into the en-
gine based on the IAC valve pintle position, the throttle
valve opening, and the calibrated vacuum loss through ac-
cessories. The minimum throttle valve position is set at the
factory with a stop screw. This setting allows enough air-
flow by the throttle valve to cause the IAC valve pintle to
be positioned a calibrated number of steps (counts) from
the seat during ”controlled” idle operation. The minimum
throttle valve position setting on this engine should not be
considered the ”minimum idle speed,” as on other fuel in-
jected engines. The throttle stop screw is covered with a
plug at the factory following adjustment.
If the IAC valve is suspected as the cause of improper idle
speed, refer to ”Idle Air Control System Check” in this sec-
tion.
MANIFOLD ABSOLUTE PRESSURE
SENSOR
The Manifold Absolute Pressure (MAP) sensor measures
the changes in the intake manifold pressure which result
from engine load and speed changes. It converts these to
a voltage output.

ENGINE CONTROLS 1F – 627
DAEWOO V–121 BL4
A closed throttle on engine coast down produces a rela-
tively low MAP output. MAP is the opposite of vacuum.
When manifold pressure is high, vacuum is low. The MAP
sensor is also used to measure barometric pressure. This
is performed as part of MAP sensor calculations. With the
ignition ON and the engine not running, the engine control
module (ECM) will read the manifold pressure as baromet-
ric pressure and adjust the air/fuel ratio accordingly. This
compensation for altitude allows the system to maintaindriving performance while holding emissions low. The
barometric function will update periodically during steady
driving or under a wide open throttle condition. In the case
of a fault in the barometric portion of the MAP sensor, the
ECM will set to the default value.
A failure in the MAP sensor circuit sets a diagnostic trouble
code P0107 or P0108.
The following tables show the difference between absolute pressure and vacuum related to MAP sensor output, which
appears as the top row of both tables.
MAP
Volts4.94.43.83.32.72.21.71.10.60.30.3
kPa1009080706050403020100
in. Hg29.626.623.720.717.714.811.88.95.92.90
VACUUM
Volts4.94.43.83.32.72.21.71.10.60.30.3
kPa0102030405060708090100
in. Hg02.95.98.911.814.817..720.723.726.729.6
ENGINE CONTROL MODULE
The engine control module (ECM), located inside the pas-
senger kick–panel, is the control center of the fuel injection
system. It constantly looks at the information from various
sensors and controls the systems that affect the vehicle’s
performance. The ECM also performs the diagnostic func-
tions of the system. It can recognize operational problems,
alert the driver through the Malfunction Indicator Lamp
(MIL), and store diagnostic trouble code(s) which identify
problem areas to aid the technician in making repairs.
There are no serviceable parts in the ECM. The calibra-
tions are stored in the ECM in the Programmable Read–
Only Memory (PROM).
The ECM supplies either 5 or 12 volts to power the sensors
or switches. This is done through resistances in the ECM
which are so high in value that a test light will not come on
when connected to the circuit. In some cases, even an or-
dinary shop voltmeter will not give an accurate reading be-
cause its resistance is too low. You must use a digital volt-
meter with a 10 megohm input impedance to get accurate
voltage readings. The ECM controls output circuits such
as the fuel injectors, the idle air control valve, the A/C
clutch relay, etc., by controlling the ground circuit through
transistors or a device called a ”quad–driver.”
FUEL INJECTOR
The Multiport Fuel Injection (MFI) assembly is a solenoid–
operated device controlled by the engine control module
(ECM). It meters pressurized fuel to a single engine cylin-
der. The ECM energizes the fuel injector or the solenoid
to a normally closed ball or pintle valve. This allows fuel toflow into the top of the injector, past the ball or pintle valve,
and through a recessed flow director plate at the injector
outlet.
The director plate has six machined holes that control the
fuel flow, generating a conical spray pattern of finely atom-
ized fuel at the injector tip. Fuel from the tip is directed at
the intake valve, causing it to become further atomized
and vaporized before entering the combustion chamber.
A fuel injector which is stuck partially open will cause a loss
of fuel pressure after the engine is shut down. Also, an ex-
tended crank time will be noticed on some engines. Diesel-
ing can also occur because some fuel can be delivered to
the engine after the ignition is turned OFF.
KNOCK SENSOR
The knock sensor detects abnormal knocking in the en-
gine. The sensor is mounted in the engine block near the
cylinders. The sensor produces an AC output voltage
which increases with the severity of the knock. This signal
is sent to the engine control module (ECM). The ECM then
adjusts the ignition timing to reduce the spark knock.
ROUGH ROAD SENSOR
The engine control module (ECM) receives rough road in-
formation from the VR sensor. The ECM uses the rough
road information to enable or disable the misfire diagnos-
tic. The misfire diagnostic can be greatly affected by
crankshaft speed variations caused by driving on rough
road surfaces. The VR sensor generates rough road infor-
mation by producing a signal which is proportional to the
movement of a small metal bar inside the sensor.
If a fault occurs which causes the ECM to not receive
rough road information between 30 and 80 mph (50 and
132 km/h), DTC P1391 will set.

1F – 630IENGINE CONTROLS
DAEWOO V–121 BL4
COMPREHENSIVE COMPONENT
MONITOR DIAGNOSTIC OPERATION
Comprehensive component monitoring diagnostics are
required to monitor emissions–related input and output
powertrain components.
Input Components
Input components are monitored for circuit continuity and
out–of–range values. This includes rationality checking.
Rationality checking refers to indicating a fault when the
signal from a sensor does not seem reasonable, i.e.
Throttle Position (TP) sensor that indicates high throttle
position at low engine loads or Manifold Absolute Pressure
(MAP) voltage. Input components may include, but are not
limited to, the following sensors:
S Vehicle Speed Sensor (VSS).
S Crankshaft Position (CKP) sensor.
S Throttle Position (TP) sensor.
S Engine Coolant Temperature (ECT) sensor.
S Camshaft Position (CMP) sensor.
S Manifold Absolute Pressure (MAP) sensor.
In addition to the circuit continuity and rationality check,
the ECT sensor is monitored for its ability to achieve a
steady state temperature to enable closed loop fuel con-
trol.
Output Components
Output components are diagnosed for proper response to
control module commands. Components where functional
monitoring is not feasible will be monitored for circuit conti-
nuity and out–of–range values if applicable. Output com-
ponents to be monitored include, but are not limited to the
following circuit:
S Idle Air Control (IAC) Motor.
S Control module controlled EVAP Canister Purge
Valve.
S A/C relays.
S Cooling fan relay.
S VSS output.
S MIL control.
Refer to ”Engine Control Module” and Sensors in this sec-
tion.
Passive and Active Diagnostic Tests
A passive test is a diagnostic test which simply monitors
a vehicle system or component. Conversely, an active
test, actually takes some sort of action when performing
diagnostic functions, often in response to a failed passive
test. For example, the Exhaust Gas Recirculation (EGR)
diagnostic active test will force the EGR valve open during
closed throttle deceleration and/or force the EGR valve
closed during a steady state. Either action should result in
a change in manifold pressure.
Intrusive Diagnostic Tests
This is any on–board test run by the Diagnostic Manage-
ment System which may have an effect on vehicle perfor-
mance or emission levels.
Warm–Up Cycle
A warm–up cycle means that engine temperature must
reach aminimum of 160°F (70°C) and rise at least 72°F
(22°C) over the course of a trip.
Freeze Frame
Freeze Frame is an element of the Diagnostic Manage-
ment System which stores various vehicle information at
the moment an emissions–related fault is stored in
memory and when the Malfunction Indicator Lamp (MIL)
is commanded on. These data can help to identify the
cause of a fault.
Failure Records
Failure Records data is an enhancement of the EOBD
Freeze Frame feature. Failure Records store the same ve-
hicle information as does Freeze Frame, but it will store
that information for any fault which is stored in onboard
memory, while Freeze Frame stores information only for
emission–related faults that command the MIL on.
COMMON EOBD TERMS
Diagnostic
When used as a noun, the word diagnostic refers to any
on–board test run by the vehicle’s Diagnostic Manage-
ment System. A diagnostic is simply a test run on a system
or component to determine if the system or component is
operating according to specification. There are many diag-
nostics, shown in the following list:
S Misfire
S Front Heated Oxygen Sensor (HO2S1)
S Rear Heated Oxygen Sensor (HO2S2)
S Exhaust Gas Recirculation (EGR)
S Catalyst monitoring
Enable Criteria
The term ”enable criteria” is engineering language for the
conditions necessary for a given diagnostic test to run.
Each diagnostic has a specific list of conditions which
must be met before the diagnostic will run.
”Enable criteria” is another way of saying ”conditions re-
quired.”
The enable criteria for each diagnostic is listed on the first
page of the Diagnostic Trouble Code (DTC) description
under the heading ”Conditions for Setting the DTC.” En-
able criteria varies with each diagnostic and typically in-
cludes, but is not limited to, the following items:
S Engine speed.
S Vehicle speed
S Engine Coolant Temperature (ECT)
S Manifold Absolute Pressure (MAP)

POSITION OF CONNECTORS AND GROUNDSW2–3
2) CONNECTOR INFORMATION
Connector
Number
Te r m i n a l
NumberColorConnecting Wiring
HarnessConnector Position
C10121 PinWhiteBody
Engine Fuse BlockEngine Fuse Block
C10211 P i nWhiteBody
Engine Fuse BlockEngine Fuse Block
C10310 PinWhiteEngine
Engine Fuse BlockEngine Fuse Block
C10424 PinWhiteFront
Engine Fuse BlockEngine Fuse Block
C1054 PinWhiteBody
Engine Fuse BlockEngine Fuse Block
C10620 PinWhiteEngine
Engine Fuse BlockEngine Fuse Block
C1072 PinWhiteABS
Engine Fuse BlockEngine Fuse Block
C10824 PinBlackBody
EngineLeft Engine Fuse Block
C1094 PinWhiteEngine
FrontUnder Engine Fuse Block
C11012 PinWhiteABS
BodyBelow Engine Fuse Block
C 1112 PinBlackABS
FrontBelow Engine Fuse Block
C1122 PinBlackFront – HornCenter Cross Member Panel
C11316 PinBlackBody
FrontBehind ECM Bracket
C20176 PinBlackI.P
I.P Fuse BlockI.P Fuse Block
C20289 PinWhiteI.P
BodyLeft CO–Driver Leg Room
C2048 PinWhiteRoof
Body (W/O Rain Sensor)Left CO–Driver Leg Room
C20414 PinWhiteRoof
Body(W/ Rain Sensor)Left CO–Driver Leg Room
C20622 PinWhiteI.P
TCMUpper Driver Leg Room
C2076 PinWhiteAir Bag
I.PUpper Left Driver Leg Room
C20815 PinWhiteI.P
FAT CBehind Glove Box
C20920 PinBlackFAT C
FAT C . A u xBetween Heater Core and
Evaporator Core
C2106 PinWhiteI.P
ConsoleBelow Console Box
C3018 PinWhiteAir Bag
BodyFront SDM
C3024 PinBlackRR. ABS
BodyCenter Rear Cross Member
C35133 PinGrayBody
Front Light DoorUnder CO–Driver A Pillar
C36133 PinGrayBody
Front Right DoorUnder Driver A Pillar
C37112 PinWhiteBody
Rear Light DoorUnder Left B Pillar
C38112 PinWhiteBody
Rear Right DoorUnder Right B Pillar
C401 (N/B)8 PinWhiteTrunk
BodyInside Right Trunk Side Cover
C401 (H/B)6 PinWhiteTrunk
BodyInside Right Trunk Side Cover
C4026 PinWhiteTrunk LID
BodyInside Right Trunk Side Cover
C4036 PinWhiteT/Gate. EXT. – BodyInside Left C Pillar
C4048 PinWhiteT/Gate. EXT. – BodyInside Left C Pillar
C4058 PinWhiteT/Gate. EXT. – T/GateBeside Left Rear Wiper Motor
C4066 PinWhiteT/Gate. EXT. – T/GateBeside Left Rear Wiper Motor
3) GROUND INFORMATION
Ground Number
Wiring HarnessGround Position
G101FrontBehind Left Head Lamp
G102FrontBehind Right Head Lamp
G103BatteryLeft Battery
G104EngineUnder Start Motor
G105BatteryUnder Start Motor
G106ABSBelow EBCM
G107Engine(MR–140/HV–240)Under Start Motor
G201I.PLeft I/P Fuse Block
G202Air BagBehind Left Audio Bracket
G203I.PBehind Left Audio Bracket
G205RoofUpper Driver Leg Room
G301BodyBelow Driver Cross Member Floor Panel
G302BodyBelow Left C Pillar
G303BodyBelow Left CO–Driver Leg Room
G401TrunkCenter Trunk Lower Back Panel
G402T/Gate. EXT.Inside Driver C Pillar
4) SPLICE PACK INFORMATION
Splice Pack Number
ColorWiring HarnessGround Position
S101BlackEngine(MR–140/HV–240)Upper Transmission
S202BlackI.PBehind Cluster
S203RedI.PBehind Audio Mounting
S204MagentaI.PBehind Audio Mounting
S205OrangeTCM (MR–140/HV–240)Upper Driver Leg Room
S301BlueBodyLeft CO–Driver Leg Room
S302BrownBodyLeft CO–Driver Leg Room

POSITION OF CONNECTORS AND GROUNDSW2–7
5) W/H BATTERY
– SIRIUS D4
– MR–140 / HV–240
6) W/H ABS
7) W/H REAR ABS

2B – 10IWHEEL ALIGNMENT
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
FOUR WHEEL ALIGNMENT
The first responsibility of engineering is to design safe
steering and suspension systems. Each component must
be strong enough to withstand and absorb extreme pun-
ishment. Both the steering system and the front and the
rear suspension must function geometrically with the body
mass.
The steering and the suspension systems require that the
front wheels self–return and that the tire rolling effort and
the road friction be held to a negligible force in order to al-
low the customer to direct the vehicle with the least effort
and the most comfort.
A complete wheel alignment check should include mea-
surements of the rear toe and camber.
Four–wheel alignment assures that all four wheels will be
running in precisely the same direction.
When the vehicle is geometrically aligned, fuel economy
and tire life are at their peak, and steering and perfor-
mance are maximized.
TOE
Toe–in is the turning in of the tires, while toe–out is the
turning out of the tires from the geometric centerline or
thrust line. The toe ensures parallel rolling of the wheels.
The toe serves to offset the small deflections of the wheel
support system which occur when the vehicle is rolling for-
ward. The specified toe angle is the setting which achieves
0 degrees of toe when the vehicle is moving.
Incorrect toe–in or toe–out will cause tire wear and re-
duced fuel economy. As the individual steering and sus-
pension components wear from vehicle mileage, addition-
al toe will be needed to compensate for the wear.
Always correct the toe dimension last.
CASTER
Caster is the tilting of the uppermost point of the steering
axis either forward or backward from the vertical when
viewed from the side of the vehicle. A backward tilt is posi-
tive, and a forward tilt is negative. Caster influences direc-
tional control of the steering but does not affect tire wear.
Weak springs or overloading a vehicle will affect caster.
One wheel with more positive caster will pull toward the
center of the car. This condition will cause the car to move
or lean toward the side with the least amount of positive
caster. Caster is measured in degrees and is not adjust-
able.
CAMBER
Camber is the tilting of the top of the tire from the vertical
when viewed from the front of the vehicle. When the tires
tilt outward, the camber is positive. When the tires tilt in-
ward, the camber is negative. The camber angle is mea-
sured in degrees from the vertical. Camber influences
both directional control and tire wear.
If the vehicle has too much positive camber, the outside
shoulder of the tire will wear. If the vehicle has too much
negative camber, the inside shoulder of the tire will wear.
Camber is not adjustable.
STEERING AXIS INCLINATION
Steering Axis Inclination (SAI) is the tilt at the top of the
steering knuckle from the vertical. Measure the SAI angle
from the true vertical to a line through the center of the strut
and the lower ball joint as viewed from the front of the ve-
hicle.
SAI helps the vehicle track straight down the road and as-
sists the wheel back into the straight ahead position. SAI
on front wheel drive vehicles should be negative.
INCLUDED ANGLE
The included angle is the angle measured from the cam-
ber angle to the line through the center of the strut and the
lower ball joint as viewed from the front of the vehicle.
The included angle is calculated in degrees. Most align-
ment racks will not measure the included angle directly. To
determine the included angle, subtract the negative or add
the positive camber readings to the Steering Axis Inclina-
tion (SAI).
SCRUB RADIUS
The scrub radius is the distance between true vertical and
the line through the center of the strut and lower ball joint
to the road surface. Scrub radius is built into the design of
the vehicle. Scrub radius is not adjustable.
SETBACK
The setback is the distance in which one front hub and
bearing assembly may be rearward of the other front hub
and bearing assembly. Setback is primarily caused by a
road hazard or vehicle collision.
TURNING ANGLE
The turning angle is the angle of each front wheel to the
vertical when the vehicle is making a turn.

FRONT SUSPENSION 2C – 5
DAEWOO V–121 BL4
DIAGNOSIS
STRUT DAMPENER
A strut dampener is basically a shock absorber. However, strut dampeners are easier to extend and retract by hand than
are shock absorbers.
Struts Seem Weak
ChecksAction
Check the tire pressures.Adjust the tire pressures to the specifications on the tire
placard.
Check the load conditions under which the vehicle is nor-
mally driven.Consult with the owner to confirm the owner’s understand-
ing of normal load conditions.
Check the compression and rebound effectiveness of the
strut dampener.Quickly push down and then lift up on the corner of the
bumper nearest the strut dampener being tested.
Compare the compression and rebound with those of a
similar vehicle that has an acceptable ride quality.
Replace the strut dampener, if needed.
Struts Are Noisy
ChecksAction
Check the mountings for looseness or damage.Tighten the strut dampener mounting nuts. Replace the
strut dampener, if needed.
Check the compression and rebound effectiveness of the
strut dampener.Quickly push down and then lift up on the corner of the
bumper nearest the strut dampener being tested.
Compare the compression and rebound with those of a
similar vehicle that has an acceptable ride quality.
Replace the strut dampener, if needed.
Leaks
ChecksAction
Check for a slight trace of fluid.The strut dampener is OK.
Check the integrity of the seal cover on the fully extended
strut.Replace the strut dampener.
Check for an excessive amount of fluid on the strut damp-
ener.Replace the strut dampener.

FRONT SUSPENSION 2C – 11
DAEWOO V–121 BL4
4. Remove the brake caliper from the rotor. Support
the caliper so it does not hang from the hydraulic
brake hose. Refer to Section 4D, Front Disc
Brakes.
5. Remove the outer tie rod from the knuckle assem-
bly. Refer to Section 6C, Power Steering Gear.
6. On vehicles equipped with the antilock braking sys-
tem (ABS), disconnect the ABS speed sensor elec-
trical connection from the knuckle.
7. Remove the ball joint pinch bolt and the nut.
8. Separate the knuckle from the ball joint using the
ball joint remover KM–507–B.
9. Remove the nuts from the bolts that connect the
knuckle assembly to the strut assembly.

2C – 12IFRONT SUSPENSION
DAEWOO V–121 BL4
Notice : Do not over extend the axle joints. When either
end of the shaft is disconnected, overextension of the joint
can result in separation of internal components and pos-
sible joint failure. Use drive axle joint seal protectors when-
ever performing service on or near the drive axles. Failure
to do so can cause internal joint or seal damage and result
in possible joint failure.
10. Support the drive axle.
11. Separate the drive axle shaft from the wheel hub.
12. Remove the bolts that connect the knuckle assem-
bly to the strut assembly.
13. Remove the knuckle assembly from the vehicle.
Installation Procedure
1. Install the knuckle assembly onto the vehicle.
2. Install the steering knuckle–to–strut assembly nuts.
Tighten
Tighten the steering knuckle–to–strut assembly nuts
to 120 NSm (89 lb–ft).
3. Connect the drive axle to the front wheel hub.
4. Connect the ball joint to the knuckle assembly.
5. Install the ball joint pinch bolt and the nut.
Tighten
Tighten the ball joint pinch bolt nut to 60 NSm (44 lb–
ft).
6. Connect the ABS speed sensor electrical connec-
tion.