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For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Tracker - 2WD 🢒 Restraints 🢒 SIR 🢒 AIR BAG Warning Lamp Does Not Come On

Object Number: 487024 Size: MF
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SIR Handling 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 AIR BAG fuse. The ignition switch also supplies Ignition 1 voltage to the AIR BAG warning indicator using the IG fuse. The AIR BAG warning indicator is connected to the AIR BAG indicator control terminal A9 of the SDM. When the ignition switch is first turned to the ON position, the SDM responds by flashing the AIR BAG warning indicator seven times.

When measurements are requested in this table, use the J 39200 DMM with the correct terminal adapter from the J 35616 Connector Test Adapter Kit. When an inspection for proper connection is requested, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. When a wire, connector or terminal repair is requested, use the J-38125 Terminal Repair Kit and refer to Wiring Repairs in Wiring Systems.

Test Description

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

  1. This step checks to see if the malfunction is in the inflatable restraint sensing and diagnostic module (SDM) circuitry or in the instrument cluster power feed circuitry.

    2.

  2. This step checks to see if voltage is present in the AIR BAG warning indicator control circuit.

    3.

  3. This step checks to see if there is a short to B+ in the AIR BAG warning indicator control circuit.

    4.

  4. This step checks to see if the instrument cluster wiring harness connector C1 is damaged or corroded.

    5.

  5. This step checks to see if the open is due to a bad bulb.

    6.

  6. This step checks to see if there is an open or a high resistance condition in AIR BAG warning indicator control circuit.

    7.

  7. This step checks to see if power is available to the instrument cluster power feed circuit.

    8.

  8. This step determines if there is a short to ground in the instrument cluster power feed circuit or if there is a malfunctioning instrument cluster.

    9.

  9. This step checks to see if the instrument cluster wiring harness connector C1 is damaged or corroded.

    10.

  10. This step determines if there is an open or a high resistance condition in the instrument cluster power feed circuit or if there is an open or a high resistance condition in the power feed circuit to the IG fuse.

AIR BAG Warning Lamp Does Not Come On

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. Set the parking brake.
  2. Turn the ignition switch to the ON position.

Does the BRAKE indicator turn ON?

--

Go to Step 3

Go to Step 13

3

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the inflatable restraint IP module yellow 2-way connector and the inflatable restraint steering wheel module yellow 2-way connector.
  3. Disconnect the inflatable restraint sensing and diagnostic module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  4. Install the J 42113 SIR Shorting Bar Tool to the SDM wiring harness connector so that the shorting bar between terminal A9 and terminal A18 is properly lifted.
  5. Turn the ignition switch to the ON position.
  6. Use the J 39200 Digital Multimeter (DMM) to measure the voltage between terminal A9 of the SDM wiring harness connector and a known good ground.

Is the measured voltage more than the specified value?

10.0 V

Go to Step 4

Go to Step 6

4

  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. Turn the ignition switch to the ON position.
  4. Use the J 39200 to measure the voltage between terminal A9 of the SDM wiring harness connector and a known good ground.

Is the measured voltage less than the specified value?

1.0 V

Go to Step 24

Go to Step 5

5
  1. Turn the ignition switch to the OFF position.
  2. Locate and Repair the short to B+ in the AIR BAG indicator control circuit.
  3. Reconnect the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.

Is the repair complete?

--

Go to Step 25

--

6

  1. Turn the ignition switch to the OFF position.
  2. Remove the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.
  3. Check the instrument cluster connector C1 for a proper connection at terminal 7.

Is the connector damaged or corroded?

--

Go to Step 7

Go to Step 8

7

Repair the instrument cluster connector C1. Refer to Connector Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 25

--

8

Remove and inspect the AIR BAG warning indicator. Refer to Instrument Cluster Bulb Replacement in Instrument Panel, Gauges and Console.

Is the AIR BAG warning indicator functional?

--

Go to Step 10

Go to Step 9

9
  1. Replace the AIR BAG warning indicator. Refer to Instrument Cluster Bulb Replacement in Instrument Panel, Gauges and Console.
  2. Install the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.

Is the repair complete?

--

Go to Step 25

--

10

  1. Install the AIR BAG warning indicator. Refer to Instrument Cluster Bulb Replacement in Instrument Panel, Gauges and Console.
  2. Use the J 39200 to measure the resistance between terminal 7 of the instrument cluster connector C1 and terminal A9 of the SDM wiring harness connector.

Is the measured resistance within the specified value?

0-2 ohms

Go to Step 12

Go to Step 11

11
  1. Locate and repair an open or a high resistance condition in the AIR BAG indicator control circuit.
  2. Install the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.

Is the repair complete?

--

Go to Step 25

--

12

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

Is the repair complete?

--

Go to Step 25

--

13

  1. Turn the ignition switch to the OFF position.
  2. Remove the IG fuse.
  3. Inspect the fuse.

Is the fuse open?

--

Go to Step 14

Go to Step 19

14
  1. Replace the fuse.
  2. Turn the ignition switch to the ON position for 10 seconds.
  3. Turn the ignition switch to the OFF position.
  4. Remove the IG fuse.
  5. Inspect the fuse.

Is the fuse open?

--

Go to Step 15

Go to Step 18

15

  1. Disconnect the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.
  2. Use the J 39200 to measure the resistance between terminal 14 of the instrument cluster connector C1 and a known good ground.

Is the measured resistance less than the specified value?

OL

Go to Step 16

Go to Step 17

16
  1. Locate and repair a short to ground in the IG fuse output circuit. Refer to Wiring Repairs in Wiring Systems.
  2. Replace the IG fuse.

Is the repair complete?

--

Go to Step 25

--

17
  1. Replace the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.
  2. Install the IG fuse.

Is the repair complete?

--

Go to Step 25

--

18

Install the IG fuse.

Is the repair complete?

--

Go to Step 25

--

19

  1. Disconnect the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.
  2. Check the instrument cluster connector C1 for a proper connection at terminal 14.

Is the connector damaged or corroded?

--

Go to Step 20

Go to Step 21

20

Replace the instrument cluster connector C1. Refer to Connector Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 25

--

21

Use the J 39200 to measure the resistance between terminal 14 of the instrument cluster connector C1 and each terminal of the IG fuse fuseholder.

Is either reading within the specified value?

0-2 ohms

Go to Step 23

Go to Step 22

22
  1. Locate and repair an open or a high resistance condition in the IG fuse output circuit. Refer to Wiring Repairs in Wiring Systems.
  2. Install the IG fuse.

Is the repair complete?

--

Go to Step 25

--

23
  1. Repair an open or a high resistance condition in the power feed circuit to the IG fuse. Refer to Power Distribution Schematics in Wiring Systems.
  2. Install the IG fuse.

Is the repair complete?

--

Go to Step 25

--

24

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

Is the repair complete?

--

Go to Step 25

--

25
  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

--