GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 1999 🢒 S/T Isuzu - 2WD 🢒 Restraints 🢒 SRS 🢒 AIR BAG Warning Lamp Comes On Steady

Object Number: 407426 Size: SF
Cell 14: G203 and G204
Handling ESD Sensitive Parts Notice
SRS Schematic Icons
Cell 51: Power and Grounding, TBC, PARK LP, GAUGES and CRUISE Fuses
Cell 10: TURN, SIR and GAUGES Fuses
Cell 14: G203 and G204
SRS Components
Cell 47: Seat Belt Switch, Steering Wheel and IP Module
SRS Service Precautions
Handling ESD Sensitive Parts Notice

Circuit Description

When the ignition switch is first turned to the RUN position, the GAUGES fuse applies battery voltage to the AIR BAG warning lamp. The AIR BAG warning lamp is connected to the supplemental RESTRAINT INDICATOR, terminal 7. The SIR fuse applies battery voltage to the Air Bag Indicator Control, terminal 10. The supplemental restraint sensing and diagnostic module (SDM) flashes the AIR BAG warning lamp 7 times. If IGNITION is outside of the normal operating voltage range (8.2-17.1 volts), the AIR BAG warning lamp turns ON solid with no DTCs set.

Diagnostic Aids

In order to disable the shorting bar from terminal 6 to terminal 7 inside the SDM harness connector, the following two conditions must be met:

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

Test Description

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

  1. This test inspects for sufficient IGNITION 1 voltage applied to the SDM.

    2.

  2. This test inspects for excessive IGNITION 1 voltage applied to the SDM.

    3.

  3. This test inspects for a properly installed CPA.

    4.

  4. This test determines if the SDM is turning on the AIR BAG warning lamp.

    5.

  5. This test inspects for a damaged shorting bar.

    6.

  6. This test determines whether the malfunction is a short to ground in CKT 358.

    7.

  7. An open SIR fuse would cause the AIR BAG warning lamp to come ON steady.

    8.

  8. This test inspects whether a short to ground caused the SIR fuse to open.

    9.

  9. This test determines whether the short to ground is due to a short in the wiring or internal to the SDM.

    10.

  10. This test determines whether the short to ground is due to a short in the wiring or internal to the supplemental restraint IP module switch.

    11.

  11. This test inspects for a disconnected SDM.

    12.

  12. This test inspects for an open in the IGNITION 1 circuit.

AIR BAG Warning Lamp Comes On Steady

Step

Action

Value(s)

Yes

No

1

Was the SRS Diagnostic System Check performed?

--

Go to Step 2

Go to SRS Diagnostic System Check

2

  1. Turn the ignition switch to the OFF position.
  2. Connect the Scan Tool to the DLC.
  3. Turn the ignition switch to the RUN position.
  4. Request the SRS data list display.

Is IGNITION more than the specified value?

8.2 V

Go to Step 3

Go to Step 12

3

  1. Set the parking brake.
  2. Start the engine.
  3. Use the Scan Tool in order to read the SRS data list.

Is IGNITION more than the specified value?

17.1 V

Go to Charging System Check in Engine Electrical

Go to Step 4

4

  1. Turn the ignition switch to the OFF position.
  2. Inspect the supplemental restraint sensing and diagnostic module (SDM) harness connector CPA.

Is the CPA properly installed?

--

Go to Step 6

Go to Step 5

5

Properly install the CPA.

Is the repair complete?

--

Go to SRS Diagnostic System Check

--

6

  1. Disconnect the supplemental restraint steering wheel yellow 2-way connector at the base of the steering column and the IP module yellow 2-way connector located behind the glove box.
  2. Disconnect the SDM harness connector. Refer to Supplemental Restraint Sensing and Diagnostic Module Replacement .
  3. Install J 38715-96 SRS Shorting Bar Tool within the SDM harness connector.
  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 7

Go to SDM Integrity Check

7

  1. Turn the ignition switch to the OFF position.
  2. Remove J 38715-96 from the SDM harness connector.
  3. Inspect the shorting bar within the SDM harness connector.

Is the shorting bar damaged or corroded?

--

Go to Step 8

Go to Step 9

8

Replace the SDM harness connector. Refer to Wiring Repair

Is the repair complete?

--

Go to Step 28

--

9

  1. Install the J 38715-96 within the SDM harness connector.
  2. Install the CPA.
  3. Disconnect the instrument cluster. Refer to Instrument Panel (IP) Cluster Replacement in Instrument Panel, Gauges and Console.
  4. Measure the resistance from the SDM harness connector terminal 7 to ground.

Is the resistance reading less than the specified value?

OL

Go to Step 10

Go to Step 11

10

Repair a short to ground condition in CKT 358.

Is the repair complete?

--

Go to Step 29

--

11

Service the instrument cluster. Refer to Instrument Panel (IP) Cluster Replacement in Instrument Panel, Gauges and Console.

Is the repair complete?

--

Go to Step 29

 

12

  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 21

Go to Step 13

13

  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 20

Go to Step 14

14

  1. Disconnect the SDM. Refer to Supplemental Restraint Sensing and Diagnostic Module Replacement .
  2. Replace the SIR Fuse.
  3. Turn the ignition switch to the RUN position for 10 seconds.
  4. Turn the ignition switch to the OFF position.
  5. Remove the SIR Fuse.
  6. Inspect the SIR Fuse.

Is the SIR Fuse good?

--

Go to Step 19

Go to Step 15

15

Does this vehicle have a supplemental restraint IP module switch?

--

Go to Step 16

Go to Step 18

16

  1. Disconnect the supplemental restraint IP module switch. Refer to DTC B1054 Supl Rst IP Module Switch CKT Failure .
  2. Replace the SIR Fuse.
  3. Turn the ignition switch to the RUN position, wait 10 seconds, then turn the ignition switch Off.
  4. Remove and inspect the SIR Fuse.

Is the SIR Fuse good?

--

Go to Step 17

Go to Step 18

17
  1. Replace the supplemental restraint IP module switch. Refer to DTC B1054 Supl Rst IP Module Switch CKT Failure .
  2. Install the SIR Fuse.

Has the supplemental restraint IP module switch been replaced and the SIR Fuse installed?

--

Go to Step 29

--

18
  1. Repair a short to ground condition in CKT 1139.
  2. Connect the SDM.
  3. Replace the SIR Fuse.

Is the repair complete?

--

Go to Step 29

--

19
  1. Replace the SDM. Refer to Supplemental Restraint Sensing and Diagnostic Module Replacement .
  2. Install the SIR Fuse.

Is the repair complete?

--

Go to Step 29

--

20

Install the SIR Fuse.

Is the repair complete?

--

Go to Step 29

--

21

Inspect the SDM harness connector.

Is the connector securely connected to the SDM?

--

Go to Step 23

Go to Step 22

22
  1. Properly connect the SDM harness connector.
  2. Install the CPA.

Is the repair complete?

--

Go to Step 29

--

23
  1. Disconnect the supplemental restraint steering wheel yellow 2-way connector at the base of the steering column and the IP module yellow 2-way connector located behind the glove box.
  2. Disconnect the SDM. Refer to Supplemental Restraint Sensing and Diagnostic Module Replacement .
  3. Inspect for proper connection to the SDM at terminal 10.

Is the SDM harness connector terminal damaged or corroded?

--

Go to Step 24

Go to Step 25

24

Replace the SDM harness connector. Refer to Wiring Repair

Is the repair complete?

--

Go to Step 29

--

25

Inspect the SDM terminals for damage or corrosion.

Are any terminals damaged or corroded?

--

Go to Step 26

Go to Step 27

26

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

Is the repair complete?

--

Go to Step 22

--

27

Measure the resistance from the SDM harness connector terminal 10 to each terminal of the SIR Fuse fuseholder.

Is either resistance reading within the specified values?

0-5 ohms

Go to SDM Integrity Check

Go to Step 29

28

Repair an open condition in CKT 1139.

Is the repair complete?

--

Go to Step 29

--

29
  1. Reconnect all the SRS components.
  2. Ensure that all of the components are properly mounted.

Have all the SRS components been reconnected and properly mounted?

--

Go to SRS Diagnostic System Check

--