DAEWOO LACETTI 2004 Service Repair Manual

SUPPLEMENTAL INFLATABLE RESTRAINTS (SIR) 8B – 7
DAEWOO V–121 BL4
DTC Description
57Passenger Side Airbag Deployment Loop Resistance Is Low
58Passenger Side Airbag Deployment Loop Is Shorted To Ground
59Passenger Airbag Deployment Loop Is Shorted To Power
80Driver Side Airbag Sensor Loop Is Shorted To Power
81Driver Side Airbag Sensor Loop Is Shorted To Ground
82Driver Side Airbag Sensor Communication Error
83Driver Side Airbag Sensor Failure
84Passenger Side Airbag Sensor Loop Is Shorted To Power
85Passenger Side Airbag Sensor Loop Is Shorted To Ground
86Passenger Side Airbag Sensor Communication Error
87Passenger Side Airbag Sensor Failure
SCAN TOOL DIAGNOSTICS
A scan tool can read serial data from terminal 13 of the
data link connector(DLC). The scan tool is used to read
diagnostic trouble codes(DTCs), and to clear some DTCs
after a repair is completed. By design, DTC 51 can not becleared. And the DTC 61 can not be cleared for the ignition
cycle once the DTC has been detected by the SDM.
To use the scan tool, turn the ignition OFF, connect the
scan tool to the DLC, and turn the ignition switch to ON.
Follow the instructions in the scan tool manual. The SDM
sends serial data from terminal 9 of the SDM to terminal
13 of the DLC.

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

SUPPLEMENTAL INFLATABLE RESTRAINTS (SIR) 8B – 9
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
61. Disconnect the connector from the SDM.2.
Check the wiring shortage between the termi-
nal5 of the SDM connector and the terminal 1
of the connector C207.
2. Is the wiring shorted? Then, replace the airbag
wiring.––Go to Step 7
71. Check the wiring shortage between the termi-
nal 13, 5 of the DLC and the ground G202.
2. Is the wiring shorted? Then, repair the wiring.––Go to Step 8
81. Confirm the ignition switch ON.
2. Check the voltage from the cigar lighter socket.
Is the voltage in the range of 11~14 voltages?–Go to Step 10–
91. Repair the wiring of cigar lighter socket.–––
101. Check the wiring shortage or loop open be-
tween the terminal4 of the connector C207 and
the terminal 13 of the data link connec-
tor(DLC).
2. Is the wiring opened or shorted?–Go to Step 11Go to Step 12
11Repair the wiring.–––
121. Check the wiring shortage or loop open be-
tween the terminal4 of the connector C207 and
the terminal 9 of the SDM wiring connector.
2. Is the wiring opened or shorted?–Replace the
airbag wiring.Replace the
SDM.

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”–

SUPPLEMENTAL INFLATABLE RESTRAINTS (SIR) 8B – 11
DAEWOO V–121 BL4
Hot In Run and Start
J3B18B03
LT BLU
LT BLU
”13” Ter.
DLC
(Data Link Connector) YEL YEL
10A
1C207 PNKPNKPNK
BLK/
WHTBRN
SDM F1
Hot in Run and Start
3
65
97 17
10A F4
32
B15
B7A19 31C201
G202
C207 4

8B – 12ISUPPLEMENTAL INFLATABLE RESTRAINTS (SIR)
DAEWOO V–121 BL4
J3B18B04
1 2
21
SDM Driver Airbag Module
Clock SpringDK GRN/
WHT
BLK/WHT
G202
10 11146
Passenger Airbag Module
BRN
BRNDK BLU
WHT/
BLK
DK BLU
13
12
DIAGNOSTIC TIC TROUBLE CODE (DTC) 1
DRIVER AIRBAG DEPLOYMENT LOOP RESISTANCE IS
HIGH
Circuit Description
When the ignition switch is turned to ON, the sensing and
diagnostic module(SDM) will perform turn–on test to diag-
nose critical malfunctions within SDM itself.
Upon passing these test ignition and deployment loop volt-ages are measured to ensure that they are within their nor-
mal voltage ranges. The SDM monitors the voltages at the
driver low and the passenger low to detect shorts to
ground or voltage in the deploy loops.
DTC 1 Will Set When
S The resistance of driver airbag deployment loop is
higher than 4.7 ohms.

SUPPLEMENTAL INFLATABLE RESTRAINTS (SIR) 8B – 13
DAEWOO V–121 BL4
DTC 1
Driver Airbag Deployment Loop Resistance Is High
CAUTION : The sensing and diagnostic module(SDM)
can maintain sufficient voltage to deploy the airbags
and pretensioners for 1 minute after the ignition is
OFF and the fuse has been removed. If the airbags
and pretensioners are not disconnected, do not be-
gin service until one minute has passed after discon-
necting power to 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
1Perform the SIR Diagnostic System Check.
Is the SIR Diagnostic System Check completed?–Go to Step 2–
2Visually inspect the connector and the wiring of driv-
er airbag. Is the connector disconnected?–Connect the
connector and
go to Step 1Go to Step 3
31. Confirm the ignition switch ”OFF”.
2. Remove the driver airbag module.
3. Disconnect the connector of SDM wiring.
4. Check the resistance between the terminal
10,11 of SDM and the terminal 1,2 of driver
airbag module. Is the resistance about 0(zero)
?
0 WGo to Step 4Go to Step 5
41. Replace the SDM.
2. Confirm the ignition switch ”ON”.
3. Erase the DTC using scan tool.
4. Perform the SIR Diagnostic System Check.
5. If the DTC is not removable, then replace the
driver airbag module.–––
51. Remove the connector from the clock spring
wiring.
2. Check the resistance between the terminal
10,11 of SDM and the terminal 1,2 of clock
spring. Is the resistance about 0(zero) ?
0 WGo to Step 6Go to Step 7
61. Replace the clock spring–––
71. Replace the airbag wiring.–––

8B – 14ISUPPLEMENTAL INFLATABLE RESTRAINTS (SIR)
DAEWOO V–121 BL4
J3B18B04
1 2
21
SDM Driver Airbag Module
Clock SpringDK GRN/
WHT
BLK/WHT
G202
10 11146
Passenger Airbag Module
BRN
BRNDK BLU
WHT/
BLK
DK BLU
13
12
DIAGNOSTIC TROUBLE CODE (DTC) 2
DRIVER AIRBAG DEPLOYMENT LOOP RESISTANCE IS
LOW
Circuit Description
When the ignition switch is turned to ON, the sensing and
diagnostic module(SDM) will perform turn–on test to diag-
nose critical malfunctions within SDM itself.
Upon passing these test ignition and deployment loop volt-
ages are measured to ensure that they are within their nor-mal voltage ranges. The SDM monitors the voltages at the
driver low and the passenger low to detect shorts to
ground or voltage in the deploy loops.
DTC 2 Will Set When
S The resistance of driver airbag deployment loop is
lower than 1.8 ohms.
S The shorting bar is damaged and then the SDM
must be replaced .

SUPPLEMENTAL INFLATABLE RESTRAINTS (SIR) 8B – 15
DAEWOO V–121 BL4
DTC 2
Driver Airbag Deployment Loop Resistance Is Low
CAUTION : The sensing and diagnostic module(SDM)
can maintain sufficient voltage to deploy the airbags
and pretensioners for 1 minute after the ignition is
OFF and the fuse has been removed. If the airbags
and pretensioners are not disconnected, do not be-
gin service until one minute has passed after discon-
necting power to 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. Confirm the ignition switch ”OFF”.
2. Wait for a minute to discharge the SDM char-
ger.–Go to Step 2–
2Visually inspect the connector and the wiring of driv-
er airbag. Is the airbag wiring damaged?–Replace the
airbag wiring.Go to Step 5
31. Confirm the ignition switch ”OFF”.
2. Remove the driver airbag module.
3. Check the resistance between the terminal 1
and 2 of driver airbag module. Is the resistance
in the specification range?
4. Erase the current DTCs with the scan tool.–Go to Step 4Go to Step 5
41. Replace the SDM.
2. Confirm the ignition switch ”ON”.
3. Erase the DTC using scan tool.
4. Perform the SIR Diagnostic System Check.
5. If the DTC is not removable, then replace the
driver airbag module.–––
51. Remove the connector from the clock spring
wiring.
2. Check the resistance between the terminal 1
and 2 of clock spring. Is the resistance ?Replace the
airbag wiring.Replace the
clock spring.

8B – 16ISUPPLEMENTAL INFLATABLE RESTRAINTS (SIR)
DAEWOO V–121 BL4
J3B18B04
1 2
21
SDM Driver Airbag Module
Clock SpringDK GRN/
WHT
BLK/WHT
G202
10 11146
Passenger Airbag Module
BRN
BRNDK BLU
WHT/
BLK
DK BLU
13
12
DIAGNOSTIC TROUBLE CODE (DTC) 3
DRIVER AIRBAG DEPLOYMENT LOOP IS SHORTED TO
GROUND
Circuit Description
When the ignition switch is turned to ON, the sensing and
diagnostic module(SDM) will perform turn–on test to diag-
nose critical malfunctions within SDM itself.
Upon passing these test ignition and deployment loop volt-
ages are measured to ensure that they are within their nor-
mal voltage ranges. The SDM monitors the voltages at the
driver low and the passenger low to detect shorts to
ground or voltage in the deploy loops.If the resistance is in the 2 kilo ohms between 10 kilo ohms,
the defect may occur depending upon SDM. The normal
resistance is over 10 kilo ohms.
DTC 3 Will Set When
S The airbag wiring of driver’s high is shorted to
ground.
S The airbag wiring of driver’s low is shorted to
ground.