2004 DAEWOO LACETTI driver

8B – 6ISUPPLEMENTAL INFLATABLE RESTRAINTS (SIR)
DAEWOO V–121 BL4
DIAGNOSIS
DIAGNOSTIC TROUBLE CODE (DTC)
When the sensing and diagnostic module (SDM) detects
any problem it illuminates the airbag warning indicator and
stores the diagnostic trouble codes (DTCs).
The supplemental inflatable restraints (SIR) diagnostic
system check must be always the starting point for any
SIR diagnosis. The diagnostic system check reveals diag-
nostic trouble codes (DTCs) through the use of scan tool.
It also checks for proper airbag warning lamp operation.
The two types of DTCs that may be recorded are as fol-lows :
1. Active DTCs represent malfunction being detected
during the current ignition cycle. Active DTCs are
stored in random access memory (RAM).
2. Historic DTCs represent malfunctions detected sin-
cethe last time the historic memory was cleared.
Historic DTCs are stored in the electrically erasable
programmable read–only memory (EPROM).
Diagnostic Trouble Code Table
DTCDescription
1Driver Airbag Deployment Loop Resistance Is High
2Driver Airbag Deployment Loop Resistance Is Low
3Driver Airbag Deployment Loop Is Shorted To Ground
4Driver Airbag Deployment Loop Is Shorted To Power
5Passenger Airbag Deployment Loop Resistance Is High
6Passenger Airbag Deployment Loop Resistance Is Low
7Passenger Airbag Deployment Loop Is Shorted To Ground
8 Passenger Airbag Deployment Loop Is Shorted To Power
9Driver Belt Pretensioner Deployment Loop Resistance Is High
10Driver Belt Pretensioner Deployment Loop Resistance Is Low
11Driver Belt Pretensioner Deployment Loop Is Shorted To Ground
12 Driver Belt Pretensioner Deployment Loop Is Shorted To Power
13Passenger Belt Pretensioner Deployment Loop Resistance Is High
14Passenger Belt Pretensioner Deployment Loop Resistance Is Low
15Passenger Belt Pretensioner Deployment Loop Is Shorted To Ground
16Passenger Belt Pretensioner Deployment Loop Is Shorted To Power
23Battery Voltage High
24 Battery Voltage Low
25 Airbag Warning Lamp Failure
31Internal Sensing Diagnostic Module(SDM) Failure
32 Airbag Inflation Record By Frontal Collision
33 Driver Side Airbag Inflation Record By Side Impact
34Passenger Side Airbag Inflation Record By Side Impact
35Belt Pretensioner Explosion Record
38Side Airbag And Belt Pretensioner Explosion Count Over 5
52 Driver Side Airbag Deployment Loop Resistance Is High
53Driver Side Airbag Deployment Loop Resistance Is Low
54Driver Side Airbag Deployment Loop Is Shorted To Ground
55 Driver Side Airbag Deployment Loop Is Shorted To Power
56Passenger Side Airbag Deployment Loop Resistance Is High

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 – 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.

SUPPLEMENTAL INFLATABLE RESTRAINTS (SIR) 8B – 17
DAEWOO V–121 BL4
DTC 3
Driver Airbag Deployment Loop Is Shorted To Ground
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 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 high, low
wiring of driver airbag module and the ground.
Is the resistance 10KΩ?10 KΩGo 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 high, low
wiring of clock spring and the ground. Is the
resistance in the specification.?–Replace the
clock spring.Replace the
airbag wiring.