service indicator DAEWOO LACETTI 2004 Service User Guide

ANTILOCK BRAKE SYSTEM 4F – 65
DAEWOO V–121 BL4
GENERAL DESCRIPTION AND SYSTEM
OPERATION
BASIC KNOWLEDGE REQUIRED
Before using this section, it is important that you have a ba-
sic knowledge of the following items. Without this knowl-
edge, it will be difficult to use the diagnostic procedures
contained in this section.
S Basic Electrical Circuits : You should understand
the basic theory of electricity and know the mean-
ing 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.
S 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.
ABS SYSTEM COMPONENTS
The ABS 5.3 Antilock Braking System (ABS) consists of
a conventional hydraulic brake system plus antilock com-
ponents. The conventional brake system includes a vacu-
um booster, master cylinder, front disc brakes, rear lead-
ing/trailing 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, the EBD indicator (which
is connected to the parking lamp) and the rear disk brakes.
See “ABS Component Locator” in this section for the gen-
eral layout of this system.
The hydraulic unit with the attached EBCM is located be-
tween the surge tank and the fire wall on the left side of the
vehicle.
The basic hydraulic unit configuration consists of hydraulic
check valves, two solenoid valves for each wheel, a hy-
draulic pump, two accumulators, and two damper. The hy-
draulic unit controls hydraulic pressure to the front calipers
and rear wheel cylinders by modulating hydraulic pressure
to prevent wheel lockup.
Nothing in the hydraulic unit or the EBCM is serviceable.
In the event of any failure, the entire ABS unit with at-
tached EBCM must be replaced. For more information, re-
fer to ”Base Braking Mode” and ”Antilock Braking Mode”
in this section.
BASE BRAKING MODE
The baseline braking mode of the ABS 5.3 system used
in this vehicle is a diagonal split system. In this system,
one master cylinder circuit supplies pressure to the right
front and the left rear brakes; the other circuit supplies
pressure to the left front and the right rear brakes. All
valves in the hydraulic modulator are in their normal, non–
energized positions as shown in the drawings found in
”ABS System Components” in this section.

ANTILOCK BRAKE SYSTEM 4F – 71
DAEWOO V–121 BL4
TIRES AND ABS/EBD
Replacement Tires
Tire size is important for proper performance of the ABS
system. Replacement tires should be the same size, load
range, and construction as the original tires. Replace tires
in axle sets and only with tires of the same tire perfor-
mance criteria (TPC) specification number. Use of any
other size or type may seriously affect the ABS operation.
TIRES AND ABS/EBD
Notice : There is no serviceable or removable EEPROM.
The EBCM must be replaced as an assembly.
The EBCM is attached to the hydraulic unit in the engine
compartment. The controlling element of ABS 5.3 is a mi-
croprocessor–based EBCM. Inputs to the system include
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 K of Data Link Connector (DLC) for service diagnostic
tools and assembly plant 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 sole-
noids to reduce brake pressure to the wheel approaching
lockup. Once the wheel regains traction, brake pressure
is increased until the wheel again begins to approach lock-
up. This 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 (except
the serial data link), and each output for proper operation.
If it detects any system malfunction, the EBCM will store
a DTC in nonvolatile memory (EEPROM) (DTCs will not
disappear if the battery is disconnected). Refer to ”Self
Diagnostics” in this section for more detailed information.
FRONT WHEEL SPEED SENSOR
The front wheel speed sensors are of a variable reluctance
type. Each sensor is attached to the steering knuckle,
close to a toothed ring. The result, as teeth pass by the
sensor, is an AC voltage with a frequency proportional to
the speed of the wheel. The magnitude of the voltage and
frequency increase with increasing speed. The sensor is
not repairable, nor is the air gap adjustable.
FRONT WHEEL SPEED SENSOR
RINGS
The toothed ring mentioned above is pressed onto the
wheel–side (outer) constant velocity joint. Each ring con-
tains 47 equally spaced teeth. Exercise care during ser-
vice procedures to avoid prying or contacting this ring. Ex-cessive contact may cause damage to one or more teeth.
If the ring is damaged, the wheel–side constant velocity
joint must be replaced.
REAR WHEEL SPEED SENSOR AND
RINGS
The rear wheel speed sensors operate in the same man-
ner as the front wheel speed sensors. They incorporate a
length of flexible harness with the connector attached to
the end of the harness. The rear wheel speed rings are in-
corporated into the hub assemblies and cannot be re-
placed separately, but require replacement of the rear
hub/bearing assembly.
VALUE RELAY AND PUMP MOTOR
RELAY
The valve relay and the motor pump relay are located in-
side the electronic brake control module (EBCM) and are
not replaceable. If one should fail, replace the EBCM.
WIRING HARNESS
The wiring harness is the mechanism by which the elec-
tronic brake control module (EBCM) is electrically con-
nected to power and to ground, to the wheel speed sen-
sors, the fuses, the switches, the indicators, and the serial
communications port. The components, considered part
of the wiring harness, are the wires that provide electrical
interconnection, and connectors (terminals, pins, con-
tacts, or lugs) that provide an electrical/mechanical inter-
face from the wire to a system component.
INDICATORS
The electronic brake control module (EBCM) continuously
monitors itself and the other ABS components. If the
EBCM detects a problem with the system, the amber ABS
indicator will light continuously to alert the driver to the
problem. An illuminated ABS indicator indicates that the
ABS system has detected a problem that affects the op-
eration of ABS. No antilock braking will be available. Nor-
mal, non–antilock brake performance will remain. In order
to regain ABS braking ability, the ABS must be serviced.
The red BRAKE indicator will be illuminated when the sys-
tem detects a low brake fluid level in the master cylinder
or when the parking brake switch is closed (the parking
brake is engaged) or EBD system is diabled.
WARNING : EBD INDICATOR LAMP WIRING IS CON-
NECTED TO THE PARKING BRAKE LAMP. IF THE
PARKING BRAKE LAMP IS TURNED ON WHEN YOU
DRIVING, CHECKING ON WHETHER THE PARKING
BRAKE LEVER IS ENAGED OR THE BRAKE FLUID
LEVEL IS LOW. IF THE SYSTEM HAS NO PROBLEM,
THE EBD SYSTEM IS WORKING IMPROPERLY. THE
EBD SYSTEM MUST BE SERVICED.

POWER STEERING SYSTEM 6A – 3
DAEWOO V–121 BL4
MAINTENANCE AND REPAIR
ON–VEHICLE SERVICE
BLEEDING THE POWER STEERING
SYSTEM
If the power steering hydraulic system has been serviced,
an accurate fluid level reading cannot be obtained until the
air is bled from the system. Follow these steps to bleed the
air from the system.
1. Turn the wheels all the way to the left and add the
power steering fluid to the MIN mark on the fluid
level indicator.
Notice : When adding fluid or making a complete fluid
change, always use DEXRON®–II or III power steering
fluid. Failure to use the proper fluid will cause hose and
seal damage and fluid leaks.
2. Start the engine. With the engine running at fast
idle, recheck the fluid level. If necessary, add fluid
to bring the level up to the MIN mark.
3. Bleed the system by turning the wheels from side to
side without reaching the stop at either end. Keep
the fluid level at the MIN mark. The air must be
eliminated from the fluid before normal steering ac-
tion can be obtained.
4. Return the wheels to the center position. Continue
running the engine for 2 to 3 minutes.
5. Road test the car to be sure the steering functions
normally and is free from noise.
6. Recheck the fluid level as described in steps 1 and
2. Make sure the fluid level is at the MAX mark af-
ter the system has stabilized at its normal operating
temperature. Add fluid as needed.
CHECKING AND ADDING FLUID
Notice : When adding fluid or making a complete fluid
change, always use DEXRON®–II or III power steering
fluid. Failure to use the proper fluid will cause hose and
seal damage and fluid leaks.
1. The power steering fluid level is indicated either by
marks on a see–through fluid reservoir or by marks
on a fluid level indicator on the fluid reservoir cap.
2. If the fluid is warmed up to 66°C (150°F), the fluid
level should be between the MAX and MIN marks.
Add fluid as needed.
3. If the fluid is cool, 21°C (70°F), the fluid level
should be at the MIN mark. Add fluid as needed.

7B – 20IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
S Dip new O–rings in clean polyalkaline glycol refrig-
erant oil before installation.
MAINTAINING CHEMICAL STABILITY
IN THE REFRIGERATION SYSTEM
The efficient operation and the life of the air conditioning
(A/C) system is dependent upon the chemical stability of
the refrigeration system. When foreign materials, such as
dirt, air, or moisture, contaminate the refrigeration system,
they will change the stability of the refrigerant and the poly-
alkaline glycol (PAG) compressor oil. They will also affect
the pressure–temperature relationship, reduce efficient
operation, and can possibly cause interior corrosion and
abnormal wear of moving parts.
Observe the following practices to ensure chemical stabil-
ity in the system:
S Wipe away dirt or oil at and near any connection
before opening that connection. This will reduce the
chance of dirt entering the system.
S Cap, plug, or tape both sides of a connection as
soon as possible after opening the connection. This
will prevent the entry of dirt, foreign material, and
moisture.
S Keep all tools clean and dry, including the manifold
gauge set and all replacement parts.
S Use a clean and dry transfer device and container
to add polyalkaline glycol refrigerant oil. This will
ensure that the oil remains as moisture–free as
possible. Refer to ”Discharging, Adding Oil, Eva-
cuating, and Charging Procedures for A/C System”
in this section.
S Have everything you need ready to allow you to
perform all operations quickly when opening an A/C
system. Do not leave the A/C system open any lon-
ger than necessary.
S Evacuate and recharge any A/C system that has
been opened. Refer to ”Discharging, Adding Oil,
Evacuating, and Charging Procedures for A/C Sys-
tem” in this section for the instructions to perform
this procedure properly.
All service parts are dehydrated and sealed before ship-
ping. They should remain sealed until just before making
connections. All the parts should be at room temperature
before uncapping. This prevents condensation of mois-
ture from the air from entering the system. Reseal all parts
as soon as possible.
DISCHARGING, ADDING OIL,
EVACUATING, AND CHARGING
PROCEDURES FOR A/C SYSTEM
CAUTION : Use only refillable refrigerant tanks that
are authorized for the charging station being used.
The use of other tanks may cause personal injury or
void the warranty. Refer to the manufacturer’s in-
structions for the charging station.CAUTION : To avoid personal injury, always wear
goggles and gloves when performing work that in-
volves opening the refrigeration system.
A charging station discharges, evacuates, and recharges
an air–conditioning (A/C) system with one hookup. Filter-
ing the refrigerant during the recovery cycle together with
filtering during the evacuation cycle ensures a supply of
clean, dry refrigerant for A/C system charging.
S Never use the R–134a charging station on a sys-
tem charged with R–12. The refrigerants and the
oils from each system are not compatible with
those from the other system and must never be
mixed, even in the smallest amount. Mixing refriger-
ant residue will damage the equipment.
S Never use adapters which convert from one size
fitting to another. Such use allows contamination,
which may cause system failure.
Charging Station Setup and Maintenance
There are many charging stations available. All perform
the various tasks required to discharge the system and re-
cover refrigerant, evacuate the system, add a measured
amount of oil, and recharge an A/C system with a mea-
sured amount of refrigerant. Refer to the manufacturer’s
instructions for all initial setup procedures and all mainte-
nance procedures.
Control Panel Functions
A charging station will have controls and indicators to allow
the operator to control and monitor the operation in prog-
ress. Refer to the manufacturer’s instructions for details.
These can be expected to include the following:
1. Main Power Switch
S Supplies electrical power to the control panel.
2. Display
S Shows the time programmed for vacuum.
S Shows the weight of the refrigerant programmed
for recharging.
S Refer to the manufacturer’s instructions for de-
tailed programming information.
3. Low–Side Manifold Gauge
S Shows the system’s low–side pressure.
4. High–Side Manifold Gauge
S Shows the system’s high–side pressure.
5. Controls Panel
S Controls the various operating functions.
6. Low–Side Valve
S Connects the low side of the A/C system to the
unit.
7. Moisture Indicator
S Shows whether the refrigerant is wet or dry.
8. High–Side Valve
S Connects the high side of the A/C system to the
unit.

8B – 8ISUPPLEMENTAL INFLATABLE RESTRAINTS (SIR)
DAEWOO V–121 BL4
SIR DIAGNOSTIC SYSTEM CHECK
Notice : If the vehicle interior has been exposed to exten-
sive water intrusion such as water leaks, driving through
high water, flooding, or other causes, the sensing and
diagnostic module(SDM) and SDM connector may need
to be replaced. With ignition OFF, inspect the area around
the SDM, including the carpet. If any significant soaking or
evidence of previous soaking is detected, the water must
be removed, water damage repaired, and the SDM and
the SDM connector must be replaced. Before attempting
any of these repairs, the supplemental inflatable re-
straints(SIR) must be disabled. Refer to ”Disabling the
SIR” and ”Sensing and Diagnostic Module(SDM)” in this
section for instructions on how to disable the SIR and re-
place the SDM.
The SIR Diagnostic System Check must always be the
starting point for any SIR diagnosis. The Diagnostic Sys-
tem Check reveals diagnostic trouble codes(DTCs)
through the use of scan tool. The diagnostic procedures
used in this section are designed to find any repair SIR
conditions. To get the best results, it is important to use the
diagnostic charts and follow the sequence listed below.
1. Perform the SIR Diagnostic System Check, which
reveal diagnostic trouble codes(DTCs) through theuse of scan tool.. It also checks for proper airbag
indicator operation.
2. Refer to the proper diagnostic chart as directed by
SIR Diagnostic System Check. Bypassing these
procedures may result in extended diagnostic time,
incorrect diagnosis, and incorrect parts replace-
ment.
3. Repeat the SIR Diagnostic System Check after any
repair or diagnostic procedures have been per-
formed to ensure that the repair has been made
correctly and that no other malfunction exists.
Circiut Description
When the ignition switch is first turned to ON, ignition volt-
age is supplied from airbag fuse to find the SDM at input
terminal A1. The SDM responds by flashing the airbag in-
dicator seven times and then turning it off while the SDM
performs tests on the SIR.
Diagnostic Aids
The order in which DTCs are diagnosed is very important.
Failure to diagnose the DTCs in the order specified may
result in extended diagnostic time, incorrect diagnosis,
and incorrect parts replacement.
SIR Diagnostic System Check
CAUTION : The sensing and the diagnosis module
(SDM) can maintain surfficient voltage to deploy the
airbags and pretensioners for 1 minute after the igni-
tion is OFF and the fuse has been removed. If the air-
bags and pretensioners are not disconnected, do not
begin service until one minute has been passed after
disconnecting power to the SDM. Otherwise, injury
could result.
CAUTION : During service procedure, be very careful
when handling the SDM. Never strike or jar the SDM.Never power the supplemental inflatable re-
straints(SIR) when the SDM is not rigidly attached to
the vehicle. All SDM mounting bolts must be carefully
tightened , and the arrow on the SDM must be point
toward the front of the vehicle to ensure proper op-
eration of the SIR. The SDM could be activated if it is
powered when it is not rigidly attached to the vehicle,
resulting in unexpected deployment and possible in-
jury.
Step
ActionValue(s)YesNo
11. Turn the ignition switch ON.
2. Observe the airbag indicator as the ignition is
being turned ON. Does the indicator flash
seven times?–System OKGo to Step 2
21. Turn the ignition to LOCK and remove the key.
2. Connect the scan tool to the data link connec-
tor(DLC). Follow the directions given in the
scan tool manual.
3. Are any DTCs displayed on the scan tool?–Go to the
DTC check
procedureGo to Step 3
3Check the fuse F1 in the interior fuse box.
Is the fuse F1 blown?–Go to Step 4Go to Step 5
4Replace the fuse F1.–––
51. Disconnect the connector C207.
2. Check the wiring shortage between the fuse F1
and the terminal 1 of the connector C207.
3. Is the wiring shorted? Then, repair the wiring.––Go to Step 6

8B – 10ISUPPLEMENTAL INFLATABLE RESTRAINTS (SIR)
DAEWOO V–121 BL4
SENSING AND DIAGNOSTIC MODULE (SDM) INTEGRITY
CHECK
The following diagnostic chart must be used when all cir-
cuitry outside the sensing and diagnostic module (SDM)
has been found to operate properly, as indicated by follow-
ing the appropriate diagnostic trouble code(DTC) chart.
The chart verifies the need for SDM replacement.
Circuit Description
When the SDM recognizes ignition voltage greater than 9
volts at terminal A1 of the SDM, the airbag indicator
flashes seven times to verify operation. At this time the
SDM performs turn–on tests followed by resistance mea-surement tests and continuous monitoring tests.
When malfunction is detected, the SDM sets current DTC
and illuminates the airbag indicator.
When the malfuncation is no longer detected and/or the
ignition switch is cycled, the SDM will clear current DTCs
and move them to a history file, except for the DTCs 51
and sometimes 71. DTCs 51 will not be cleared by scan
tool because these codes require replacement of SDM.
The SDM must be replaced only after the malfunction that
set the DTC has been repaired.
Sensing and Diagnostic Module (SDM) Integrity Check
CAUTION : The sensing and diagnostic module
(SDM) can maimtain sufficient voltage to deploy the
airbags and pretensioners for 1 minute after the igni-
tion is OFF and the fuse has been removed. If the air-
bags and pretensioners are not disconnected, do not
begin service until one minute has passed after dis-
connecting the power to the SDM. Otherwise, injury
could result.
CAUTION : During service procedure, be very careful
when handling the SDM. Never strike or jar the SDM.Never power the supplemental inflatable re-
straints(SIR) when the SDM is not rigidlyattached to
the vehile. All SDM mounting bolts must be carefully
tightened , and the arrow on the SDM must be point
toward the front of the vehicle to ensure proper op-
eration of the SIR. The SDM could be activated if it is
powered when it is not rigidly attached to the vehicle,
resulting in unexpected deployment and possible in-
jury.
Step
ActionValue(s)YesNo
11. Turn the ignition to LOCK and remove the key
2. Connect all SIR components and ensure that
all the components are properly mounted.
3. Ensure that the ignition switch has been OFF
for at least 30 seconds.
4. Observe the airbag indicator as the ignition is
turned ON. Does the indicator lamp flashes
seven times ?–Clear the SIR
DTCs and
go to
”Diagnostic
System Check”Go to Step 2
21. Turn the ignition to LOCK and remove the key.
2. Connect the scan tool to DLC. Follow the direc-
tions given in the scan tool manual.
3. Turn the ignition to ON.
4. Request SIR DTC display with the scan tool. Is
the same DTC displayed that was previous oc-
curred when the SIR Diagnostic System Check
was previously performed?–Go to Step 3.Go to the table
for the DTC in-
dicated.
31. Clear SIR DTCs.
2. Turn the ignition OFF for at least 30 seconds.
3. Observe the airbag indicator as the ignition is
turned ON. Does the indicator lamp flashes
seven times ?–System OKGo to Step4
41. Turn the ignition to LOCK and remove the key.
2. Disconnect the SDM connector.
3. Replace the SDM.
4. Connect the SDM connector and ensure that
all components are properly mounted. Is the
repair complete?–Go to
”Diagnostic
System Check”–

8B – 88ISUPPLEMENTAL INFLATABLE RESTRAINTS (SIR)
DAEWOO V–121 BL4
MAINTENANCE AND REPAIR
ON–VEHICLE SERVICE
SERVICE PRECAUTION
CAUTION : The sensing and diagnostic mod-
ule(SDM) can maintain sufficient voltage to
deploy the airbags and pretensioners for 1 min-
ute after the ignition is OFF and the fuse has been
removed. If the airbags and pretensioners are not
disconnected, do not begin service until one
minute has passed after disconnecting power to
SDM. If the airbags are disconnected, service can
be excuted immediately without waiting for one–
minute time period to expire. Failure to tempo-
rarily disable the SIR during service can result in
unexpected deployment, personal injury and un-
necessary SIR repairs.
DISABLING THE SUPPLEMENTAL
INFLATABLE RESTRAINTS(SIR)
1. Turn the steering wheel to the straight–ahead posi-
tion.
2. Turn the ignition switch to LOCK and remove the
key.
3. Remove the airbag fuse F1 in the I/P fuse block
and wait more than one minute for SIR capacitor to
discharge.
ENABLING THE SUPPLEMENTAL
INFLATABLE RESTRAINTS(SIR)
1. Insert the airbag fuse F8 in the I/P fuse block.
2. Turn the ignition switch to ON and verify that the
airbag indicator flashes seven times and turns OFF.
If it does not operate as described, perform the”
SIR Diagnostic System Check” referring in this sec-
tion.
CAUTION : While turning the ignition switch,
staying well away from the inflator modules, or
personal injury can be occurred.

SUPPLEMENTAL INFLATABLE RESTRAINTS (SIR) 8B – 101
DAEWOO V–121 BL4
FRONT SEAT BELT
PRETENSIONERS
CAUTION : Tempering with seat belt pretensioner
creates the risk of an injury from unexpected deploy-
ment. Therefore, the driver airbag module should
never be disassembled.
The seat belt pretensioners(with load limiter for some ve-
hicles) are assembled with each front seat belt retractors
to retract the seat belt webbing when accounted frontal
collision. The seat belt pretensioners are controlled by
sensing and diagnostic module(SDM). The seat belt pre-
tensioner contains an igniter charge and a gas generator
to pull the seat belt webbing. The seat belt pretensioner
must be replaced after an accident that causes its activa-
tion.
The seat belt pretensioner also contains a shorting bar to
prevent current from travelling through the seat belt pre-
tensioner during servicing. The shorting bar is disengaged
when the connector is connected.
SENSING AND DIAGNOSTIC
MODULE (SDM)
CAUTION : During the service procedures, be careful
when handling the SDM. Never shake or jar the SDM.
Never apply power to SIR when the SDM is not rigidly
attached to the vehicle. All SDM mounting bolts and
grounding nuts must be fully tightened. Failure to fol-
low these precautions could cause deployment and
result in personal injury.
The SDM is located on the floor beneath the floor console
assembly. The SDM performs the following functions :
S Monitors the supplemental inflatable restraints(SIR)
electrical components and sets a diagnostic trouble
code(DTC) when malfunction is detected.
S Records any faults that are discovered.
S Displays SIR diagnostic trouble codes and system
status information when connected to a scan tool.
S Illuminates the airbag indicator to alert the driver to
any fault.S Provides a reserve power source to deploy the air-
bags and pretensioners if an accident has disabled
the normal power source.
S Monitors vehicle velocity changes to detect frontal
impacts, which are severe enough to warrant de-
ployment.
S Causes current to flow through the airbag modules
and pretensioner to cause deployment if a frontal
impact of sufficient force is detected.
The SDM contains no user–serviceable parts.
AIRBAG WARNING LAMP
The instrument cluster contains an airbag warning indica-
tor and sensing and diagnostic module(SDM). The SDM
performs a turn–on test when the ignition is turned ON.
The SDM flashes the airbag indicator seven times by sup-
plying an intermittent ground to the indicator lamp circuit.
After flashing seven times, the airbag indicator will turn off
if no more malfunctions have been detected.
If the SDM has detected malfunctions in the internal and
external circuits, which could potentially affect the opera-
tion of the supplemental inflatable restraints(SIR), the air-
bag indicator stays on. Some malfunctions could result in
non–deployment when necessary or deployment under
conditions which would not normally result in deployment.
When the SDM is not properly attached to its connector,
the airbag circuit is shorted to ground because there is a
shorting bar in the SDM electrical connector. The shorting
bar is disengaged when proper connection is made, but if
a poor connection exists the SDM connector supplied a
ground to the airbag indicator independently of the SDM,
and the airbag indicator turns on.
CLOCK SPRING
CAUTION : Disassembling the clock spring can cause
injury or cause the clock spring to malfunction.
CAUTION : Over–rotating the clock spring (over 3 and
one quarter turns to one direction) without the steer-
ing wheel in position could damage the clock spring
and result in an inoperative driver airbag.
There is a coil assembly in the steering which is referred
to as a clock spring because of its internal resemblance to
the type of spring used in a mechanical clock. The coil

8B – 102ISUPPLEMENTAL INFLATABLE RESTRAINTS (SIR)
DAEWOO V–121 BL4
spring should never be disassembled, and there is no
timekeeping function. The clock spring contains two or
three current–carrying coils. One of the current–carrying
coils maintains continuous contact within the driver de-
ployment loop while the steering wheel is rotated. The
clock spring also contains coils that maintain continuous
contact for horn and remote audio control switch circuit.
Turning the steering wheel in one direction tightens the
coil, and turning the steering wheel in the opposite direc-
tion loosens the coil. Do not turn the clock spring when the
steering wheel is not attached. Refer to ”Clock Spring” in
this section for proper installation of the clock spring.
The clock spring also includes the wiring and the connec-
tors for the horn circuit and the driver airbag circuit. A yel-
low two–way connector on the lower steering column is at-
tached to the clock spring wiring. The yellow connector to
the airbag contains a shorting bar which connects the driv-
er high circuit to driver low circuit when the connector is
disconnected.
The shorting bar prevents current from travelling through
the driver airbag module during servicing. The shorting bar
is disengaged when the clock spring connector is con-
nected.WIRING HARNESS CONNECTORS
If the sensing and diagnostic module (SDM) electrical con-
nector is not attached properly, a built in shorting bar will
connect the wire from airbag warning lamp with the SDM
ground wire. This turns on the airbag indicator . To prevent
deployment during servicing, additional shorting bars are
located in following locations :
S The clock spring electrical connector at the lower
steering column.
S The passenger airbag module.
S The driver airbag module.
S The seat belt pretensioners.
The shorting bar is only a backup safety device. Always
disable the supplemental inflatable restraints(SIR) before
beginning any service procedure.

9B – 46ILITHING SYSTEMS
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
HEADLAMPS–ON REMINDER CHIME
When the headlamp switch is in the headlamps–on or
parking lamps–on position, voltage is applied to the chime
module. When the ignition is in ON, ACC or START, volt-
age is applied through the fuse block to the module. These
two voltages are sensed, and the chime module is not
sounded.
When the ignition is not in ON, ACC or START, the module
loses voltage. The chime module senses change. If the
voltage is still available, it is applied to sound the chime.
The chime can be turned off by turning the headlamp
switch off. The module no longer senses voltage from the
headlamp switch, so the chime module does not sound.
HEADLAMPS
The headlamps are controlled by the multifunction lever
located on the left side of the steering column. They will
come on with the ignition switch in any position. Turning
the headlamp switch to the first position turns on the park-
ing lamps, the license plate lamps and the instrument pan-
el illumination. Turning the switch to the second position
turns on all of the previous lamps and the headlamps.
Turning the switch to the OFF position turns off all the
lamps.
Headlamp high beams and low beams are also controlled
by this lever. When the headlamps are on, pushing the le-
ver away from the driver until the switch clicks changes the
lamp from low beam to high beam. An indicator lamp on
the instrument cluster assembly will come on when the
high beam headlamps are on. To return the headlamps to
low beam, pull the lever toward the driver.
The headlamps must be aimed for proper illumination of
the road. Headlamp aim should be checked whenever a
new headlamp assembly is installed, or whenever service
repairs to the front end area may have disturbed the head-
lamp assembly or its mountings.
DAYTIME RUNNING LAMPS
The Daytime Running Lamps (DRL) will come on when:
S The ignition is ON.
S The light is OFF.
S The parking brake is released.
When the exterior lights are on, the DRL will turn off. To
turn the DRL off when idling, apply the parking brake.
PARKING AND TURN SIGNAL LAMPS
The parking lamps can be turned on by turning the lighting
switch to the first position. The parking lamps can be
turned off by turning the switch to the OFF position.When the turn signals are activated, the front and rear turn
signal lamps flash to signal a turn. The turn signals work
only when the ignition is ON.
The turn signals are controlled by the light switch on the
left side of the steering column. Moving the lever all the
way up or down (past the detent) will turn on the front and
rear turn signals. When the turn is completed, the lever will
return to horizontal and the turn signals will stop flashing.
For changing lanes, or for shallow turns in which the steer-
ing wheel does not turn far enough to cancel the signal,
move the signal lever only to the first detent and hold it
there. When the lever is released, it will return to horizontal
and the turn signals will cancel.
FOG LAMPS
The fog lamp switch is on the instrument panel to the right
of the steering column. To use the fog lamps, first turn on
the headlamps or the parking lamps. Then push the fog
lamp switch. The indicator light in the switch will illuminate
to indicate that the fog lamps are on. Push the switch again
to turn off the fog lamps. The indicator light will then go off.
The fog lamps should not be used as a substitute for the
headlamps.
The fog lamps must be aimed for proper illumination of the
road. Fog lamp aim should be checked when a new bulb
is installed or if service or repairs in the front end area may
have disturbed the fog lamp mountings.
REAR COMBINATION LAMPS
The taillamps, stoplamps, turn signal lamps and backup
lamp are one assembly.
Turning on either the headlamps or the parking lamps will
also turn on the taillamps. When the brake pedal is
pushed, the taillamps will glow brighter to serve as sto-
plamps.
The center high–mounted stoplamp is located in the rear
window and will come on when the brake pedal is pressed.
LICENSE PLATE LAMP
The license plate lamps will come on when the headlamps
or the parking lamps are on. The license plate lamps are
mounted above the license plate.
INTERIOR COURTESY LAMP
The courtesy lamp is located on the headliner just behind
the front seats. The lamp switch has three positions. If the
switch is left in the center position, the lamp will go on
whenever a door is opened and go off when it is closed.
In the ON position, the lamp will stay on until it is turned off.
In the OFF position, the lamp will not come on, even when
a door is opened.
LUGGAGE COMPARTMENT LAMP
The luggage compartment lamp is located under the deck
lid sill plate on the notchback. The lamp is located on the
left–side wheelhouse trim panel on the hatchback. It will
come on whenever the luggage compartment is opened.