airbag disable DAEWOO LACETTI 2004 Service Repair Manual

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 – 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 – 91
DAEWOO V–121 BL4
Important : If the vehicle interior has been exposed to ex-
tensive water intrusion such as water leaks, driving
through high water, flooding or other causes, then the
SDM and SDM connector may need to be replaced. With
the ignition OFF, inspect the area of SDM, including the
carpet. If any significant soaking or evidence of previous
soaking is detected, the water must be removed, the water
damage repaired and the SDM and SDM connector must
be replaced. Before attempting any of these repairs, the
SRS must be disabled. Refer to ”Disabling the SIR” in this
section.
Removal and Installation Procedure
1. Disable the supplemental inflatable restraints(SIR).
Refer to ”Disabling the SIR” in this section.
2. Remove the floor console. Refer to section 9G, In-
terior Trim.
3. Remove the connector position assurance lock,
which is tethered to SDM connector.
4. Disconnect the SDM electrical connector.
5. Remove the SDM mounting bolts.
6. Remove the SDM.
7. Install the removed parts in the reverse order.
Installation Notice
Tightening torque of SDM mounting bolts is 10 NSm
(89 lb–in).
Enable the SIR. Refer to”Enabling the SIR”
in this section.
CAUTION : All SDM mounting bolts must be care-
fully tightened and the arrow on the SDM must be
pointing toward the front of the vehicle to ensure
proper operation of the SIR. The SDM could be
activated if it is powered while not rigidly at-
tached to the vehicle, resulting in unexpected de-
ployment and possible injury.
0
DRIVER AIRBAG MODULE
Removal and Installation Procedure
1. Disconnect the negative battery cable.
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.
2. Remove two driver airbag module mounting bolts
and discard them.

8B – 92ISUPPLEMENTAL INFLATABLE RESTRAINTS (SIR)
DAEWOO V–121 BL4
3. Remove the connector from the driver airbag mod-
ule.
4. Remove the driver airbag module.
CAUTION : When handling an airbag module, al-
ways keep the top the unit facing upward. This
leaves room for the airbag to expand if the mod-
ule unexpectedly deploys. Without room for ex-
pansion, a module suddenly propelled toward a
person or object can cause injury or vehicle dam-
age.
5. Installation should follow the removal procedure in
the reverse order.
Installation Notice
Tightening torque of the driver airbag module mount-
ing bolt is 8 NSm (71 lb–in).
CLOCK SPRING
Removal and Installation Procedure
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.
1. Disconnect the negative battery cable.
2. Remove the driver airbag module. Refer to ”Driver
airbag module” in this section.
3. Remove the steering wheel. Refer to Section 6E,
Steering Wheel and Column.
4. Remove the screws from the upper and lower
steering column covers. And remove the covers.

8B – 94ISUPPLEMENTAL INFLATABLE RESTRAINTS (SIR)
DAEWOO V–121 BL4
PASSENGER AIRBAG MODULE
Removal and Installation Procedure
CAUTION : The sensing and diagnostic mod-
ule(SDM) can maintain sufficient voltage to
deploy the airbags and pretensioners for 1minute
after the ignition is OFF and the fuse has been re-
moved. 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.
1. Disconnect the negative battery cable.
2. Remove the glove box. Refer to 9E, Instrumenta-
tion/Driver Information.
3. Disconnect the passenger airbag yellow electrical
connector. Remove the Instrument panel.
4. Remove the passenger airbag module by removing
the mounting bolts from the airbag bracket.
5. Installation should follow the removal procedure in
the reverse order.
Tightening torque of the passenger airbag module
mounting bolt is 11 NSm (97 lb–in).

SUPPLEMENTAL INFLATABLE RESTRAINTS (SIR) 8B – 95
DAEWOO V–121 BL4
SIDE AIRBAG SENSOR
Removal and Installation Procedure
CAUTION : The sensing and diagnostic mod-
ule(SDM) can maintain sufficient voltage to
deploy the airbags and pretensioners for 1minute
after the ignition is OFF and the fuse has been re-
moved. 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 executed immediately without waiting for
one–minute time period to expire. Failure to tem-
porarily disable the SIR during service can result
in unexpected deployment, personal injury and
unnecessary SIR repairs.
1. Disconnect the negative battery cable.
2. Remove the trim from B pillar.
3. Remove the side airbag sensor mounting bolts.
4. Remove the side airbag sensor.
5. Installation should follow the removal procedure in
the reverse order.
Tightening torque of the side airbag sensor mounting
bolts is 8 NSm (71 lb–in).
FRONT SEAT BELT PRETENSIONER
For removal and installation, refer to Section 8A, Seat
Belts.
AIRBAG MODULE DEPLOYMENT
(INSIDE OF VEHICLE)
Deploy the airbags before disposing them. If a vehicle
to be scrapped, the airbag may be deployed inside the
vehicle.
CAUTION : To avoid injury while deploying an air-
bag or a pretensioner in the vehicle, observe the
following precaution :
S Before deploying the airbags, remove all loose ob-
jects from the airbag’s expansion area.
S Deploy the airbags with the vehicle doors closed
and the side windows open.
S Deploy the airbags only in an evacuated area. Ser-
vice personnel who must be present during the de-
ployment should be at least 10 meters(33 feet) in
front of the vehicle.
S Do not connect the voltage source until after having
completed all other preparations for the deployment
of airbags.
S Allow a deployed airbag module or pretensioner
cool for 30 minutes before handling.
S Wear gloves and eye protection during the disposal
procedure.
S If the deployment fails, disconnect the voltage
source and wait 5 minutes before approaching the
vehicle.

8B – 96ISUPPLEMENTAL INFLATABLE RESTRAINTS (SIR)
DAEWOO V–121 BL4
Deployment Procedure
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 executed immediately without waiting for
one–minute time period to expire. Failure to tem-
porarily disable the SIR during service can result
in unexpected deployment, personal injury and
unnecessary SIR repairs.
1. Disconnect both battery cables and place the bat-
tery at least 10 meters (33 feet) from the vehicle.
2. Remove the driver side knee bolster or instrument
panel lower cover from the steering column. Refer
to Section 9G, Interior Trim.
3. At the lower steering column, cut the two wires
leading from the supplemental inflatable re-
straints(SIR) harness to the clock spring.
4. Strip 13mm(0.5 inch) of the insulation from the end
of the wires leading to the clock spring.
5. Use two additional wires, each at least 10 me-
ters(33 feet) long, to reach from the deployment
battery to the inflator module.
6. Strip 13mm(0.5 inch) of the insulation from the end
of these two additional wires.
7. Twist the two wires together at one end.
8. Place the twisted ends of the two wires near the
deployment battery. Do not connect the wires to the
battery at this time.
9. Using the free ends of the 10 meters(33 feet) wires
leading to the clock spring, make two splices, one
at each wires from the airbag modules.
10. Wrap the wires with insulation tape.
11. Now that the free ends of the 10 meters(33 feet)
wires are spliced to the airbag module wires, and
the ends that are twisted together are near the de-
ployment battery. Clear the area.
12. Untwist the wires that near the deployment battery.
13. Touch one wire to the positive battery terminal and
touch the other wire to the negative battery termi-
nal. The airbag will deploy.
14. Repeat this procedure for the passenger airbag,
side airbags and pretensioners.
15. Using proper precautions, dispose of the deployed
airbags/pretensioners. Refer to ”Deployed Airbag
Module Disposal Procedure” in this section.

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.