GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1999 🢒 Grand Prix 🢒 Restraints 🢒 SIR 🢒 AIR BAG Warning Lamp Comes On Steady

Object Number: 380203 Size: SF
SIR Components
SIR Schematics
SIR Caution
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The ignition switch supplies Ignition 1 voltage to the inflatable restraint sensing and diagnostic module (SDM) at terminal A1 using the SIR Fuse. The ignition switch also supplies Ignition 1 voltage to the AIR BAG warning lamp using the IP-IGN Fuse. The AIR BAG warning lamp is connected to the INFLATABLE RESTRAINT INDICATOR at terminal A9 of the SDM. When the ignition switch is first turned to the RUN position, the SDM responds by flashing the AIR BAG warning lamp seven times. If IGNITION 1 is outside of the normal operating voltage range (9.0 volts-16.0 volts) for more than 40ms, the AIR BAG warning lamp will come ON solid with no DTCs set.

Diagnostic Aids

In order to disable the shorting bar from terminal A9 to terminal A18 inside the inflatable restraint sensing and diagnostic module (SDM) wiring harness connector, the following two conditions must be met:

    • The SDM wiring harness connector must be properly connected to the SDM.
    • The connector position assurance (CPA) must be properly installed in the SDM wiring harness connector.

Test Description

The numbers below refer to the step numbers on the diagnostic table:

  1. This step checks to see if the scan tool can communicate with the inflatable restraint sensing and diagnostic module (SDM).

    2.

  2. This step checks to see if sufficient IGNITION voltage is applied to the SDM.

    3.

  3. This step checks to see if excessive IGNITION voltage is applied to the SDM.

    4.

  4. This step checks to see if the retainer assembly or the shorting bar is damaged or corroded.

    5.

  5. This step checks to see if the SDM wiring harness connector terminals are damaged or corroded.

    6.

  6. This step checks to see if the SDM terminals are damaged or corroded or if the lifting tab on the SDM is damaged.

    7.

  7. This step checks to see if the SDM wiring harness connector properly connects to the SDM and if the connector position assurance (CPA) is properly installed.

    8.

  8. This step checks to see if there is a short to ground in CKT 358.

    9.

  9. This step determines if there is a short between CKT 358 and CKT 1751 or if there is a short to ground in CKT 358.

    10.

  10. This step checks to see if the SIR Fuse is OK. An open SIR Fuse would cause the AIR BAG warning lamp to come ON steady.

    11.

  11. This step checks to see if a short to ground caused the SIR Fuse to open.

    12.

  12. This step checks for a short to ground in CKT 1139.

    13.

  13. This step checks to see if the SDM wiring harness connector properly secures to the SDM.

    14.

  14. This step checks to see if there is an open in CKT 1139.

    15.

  15. This step determines if there is an open or a high resistance in the B+ feed circuit to the input side of the SIR Fuse or if there is a malfunctioning SDM.

AIR BAG Warning Lamp Comes On Steady

Step

Action

Value(s)

Yes

No

1

Was the SIR Diagnostic System Check performed?

--

Go to Step 2

Go to SIR Diagnostic System Check

2

  1. Turn the ignition switch to the OFF position.
  2. Install the scan tool.
  3. Turn the ignition switch to the RUN position.
  4. Use the scan tool to establish communication with the inflatable restraint sensing and diagnostic module (SDM).

Does the scan tool communicate with the SDM?

--

Go to Step 3

Go to Scan Tool Does Not Communicate with Sensing and Diagnostic Module

3

Use the scan tool to request the SIR scan tool data display.

Is the ignition voltage more than the specified value?

9.0 V

Go to Step 4

Go to Step 18

4

  1. Set the parking brake.
  2. Use the scan tool to request the SIR scan tool data display.

Is the ignition voltage more than the specified value?

16.0 V

Go to Battery Is Undercharged or Overcharged in Engine Electrical

Go to Step 5

5

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the SDM wiring harness connector. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  3. Use a small flat head screwdriver to remove the retainer assembly from the SDM wiring harness connector by gently lifting the locking tabs on the ends of the retainer assembly.
  4. Carefully inspect the retainer assembly and shorting bar.

Is the retainer assembly or the shorting bar damaged or corroded?

--

Go to Step 6

Go to Step 7

6
  1. Replace the retainer assembly.
  2. Follow the instructions in the GM Kit 12167318 for installation of the new retainer assembly.

Is the repair complete?

--

Go to Step 32

--

7

Carefully inspect the SDM wiring harness connector for corrosion or damaged terminals.

Are the SDM wiring harness connector terminals damaged or corroded?

--

Go to Step 8

Go to Step 9

8

Replace the damaged or corroded SDM wiring harness connector terminals. Refer to Wiring Repair .

Is the repair complete?

--

Go to Step 32

--

9

  1. Follow the instructions in the GM Kit 12167318 to properly reinstall the retainer assembly to the SDM wiring harness connector.
  2. Important: It is very important to properly inspect the SDM terminals and the shorting bar lifting tab in order to avoid misdiagnosis. Carefully inspect the SDM terminals for corrosion or damaged terminals.
  3. Also, carefully inspect the shorting bar lifting tab to ensure that it is not damaged.

Are the SDM terminals damaged or corroded or is the shorting bar lifting tab damaged?

OL

Go to Step 28

Go to Step 10

10

  1. Connect the SDM wiring harness connector to the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  2. Install the connector position assurance (CPA).

Does the SDM wiring harness connector properly connect to the SDM and is the CPA properly installed?

--

Go to Step 12

Go to Step 11

11

Replace the SDM wiring harness connector. Refer to Wiring Repair .

Is the repair complete?

--

Go to Step 32

--

12
  1. Disconnect the inline connectors C215 and C216.
  2. Disconnect the SDM wiring harness connector. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  3. Install the J 42113 SIR Shorting Bar Tool into the SDM wiring harness connector above terminal A9 and terminal A18.
  4. Install the CPA.
  5. Turn the ignition switch to the RUN position.

Does the air bag warning lamp come ON steady?

--

Go to Step 13

Go to Step 28

13

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.
  3. Use the J 39200 Digital Multimeter (DMM) to measure the resistance between terminal A9 of the SDM wiring harness connector and a known good ground.

Is the measured resistance less than the specified value?

OL

Go to Step 14

Go to Step 17

14

  1. Disconnect CKT 1751 from G205. Refer to SIR Components .
  2. Use the J 39200 to measure the resistance between terminal A9 and terminal A18 of the SDM wiring harness connector.

Is the resistance reading less than the specified value?

OL

Go to Step 16

Go to Step 15

15
  1. Locate a short to ground in CKT 358.
  2. Repair the short to ground in CKT 358.

Is the repair complete?

--

Go to Step 32

--

16
  1. Locate a short between CKT 358 and CKT 1751.
  2. Repair the short between CKT 358 and CKT 1751.
  3. Inspect CKT 1751 for any cutting or chafing.

Is the repair complete?

--

Go to Step 32

--

17

Replace the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.

Is the repair complete?

--

Go to Step 32

--

18

  1. Turn the ignition switch to the OFF position.
  2. Remove the SIR Fuse.
  3. Inspect the SIR Fuse.

Is the SIR Fuse good?

--

Go to Step 23

Go to Step 19

19

  1. Replace the SIR Fuse.
  2. Turn the ignition switch to the RUN position for 10 seconds.
  3. Turn the ignition switch to the OFF position.
  4. Remove the SIR Fuse.
  5. Inspect the SIR Fuse.

Is the SIR Fuse good?

--

Go to Step 22

Go to Step 20

20

  1. Disconnect the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  2. Use the J 39200 to measure the resistance between the output side of the SIR Fuse and a known good ground.

Is the measured resistance less than the specified value?

OL

Go to Step 21

Go to Step 28

21
  1. Locate a short to ground in CKT 1139.
  2. Repair the short to ground in CKT 1139.
  3. Replace the SIR Fuse.

Is the repair complete?

--

Go to Step 32

--

22

Install the SIR Fuse.

Is the repair complete?

--

Go to Step 32

--

23

Inspect the SDM wiring harness connector. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .

Is the connector secure?

--

Go to Step 25

Go to Step 24

24
  1. Properly connect the SDM wiring harness connector to the SDM.
  2. Install the CPA.

Is the repair complete?

--

Go to Step 32

--

25
  1. Disconnect the inline connectors C215 and C216.
  2. Disconnect the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  3. Check the SDM wiring harness connector for a proper connection at terminal A1.

Is the SDM wiring harness connector terminal A1 damaged or corroded?

--

Go to Step 26

Go to Step 27

26

Replace the SDM wiring harness connector. Refer to Wiring Repair .

Is the repair complete?

--

Go to Step 32

--

27

Inspect the SDM terminals for damage or corrosion.

Are any terminals damaged or corroded?

--

Go to Step 28

Go to Step 29

28

Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .

Is the repair complete?

--

Go to Step 32

--

29

Use the J 39200 to measure the resistance between the output side of the SIR Fuse and terminal A1 of the SDM wiring harness connector.

Is the measured resistance within the specified value?

0-2 ohms

Go to Step 31

Go to Step 30

30
  1. Locate an open or a high resistance in CKT 1139.
  2. Repair the open or the high resistance in CKT 1139.

Is the repair complete?

--

Go to Step 32

--

31

  1. Turn the ignition switch to the RUN position.
  2. Use the J 39200 to measure the voltage between the input side of the SIR Fuse and a known good ground.

Is the measured voltage within the specified value?

B+

Go to Step 28

Go to Power Distribution Schematics in Wiring Systems

32
  1. Reconnect all SIR components.
  2. Make sure that all components and connectors are properly mounted.

Have all the SIR components been reconnected and properly mounted?

--

Go to SIR Diagnostic System Check

--