GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2004 🢒 Vibe - FWD 🢒 Restraints 🢒 SIR 🢒 Air Bag Indicator Always On

Circuit Description

The ignition switch supplies battery voltage to the AIR BAG indicator using the AM2 fuse. The AIR BAG indicator is connected to the AIR BAG indicator control circuit of the SDM. When the ignition switch is first turned to the ON position, the SDM responds by illuminating the AIR BAG indicator for approximately 6 seconds while performing diagnostic tests on the SIR system.

Diagnostic Aids

Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.

The following are possible causes of the malfunction:

    • An open or high resistance in the AIR BAG indicator control circuit
    • A short to ground in the AIR BAG indicator control circuit
    • Improper or irregular supply voltage to the SDM
    • An instrument panel cluster malfunction
    • An internal SDM malfunction

If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

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

  1. Tests the AIR BAG indicator control circuit voltage.

    2.

  2. Tests the AIR BAG indicator control circuit for a short to ground.

    3.

  3. Tests the AIR BAG indicator control circuit for an open or high resistance.

Step

Action

Value(s)

Yes

No

Schematic Reference: SIR Schematics

Connector End View Reference: SIR Connector End Views

1

Did you perform a Diagnostic System Check - SIR?

 

Go to Step 2

Go to Diagnostic System Check - SIR

2
  1. Turn OFF the ignition.
  2. Disconnect the SDM connector.
  3. Inspect the SDM connector for the following conditions:
    4. • Corrosion
    • Damaged Terminals
    • Poor connections/terminal tension

Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

 

Go to Step 15

Go to Step 3

3

Is the Air Bag indicator illuminated with the ignition in the LOCK or ACC position?

 

Go to Step 7

Go to Step 4

4
  1. Disconnect the SDM connector.
  2. Turn the Ignition ON, with the engine OFF and wait at least 60 seconds.
  3. Measure the voltage of the Ignition Positive Voltage to each of the SDM ground circuits, while operating the electrical system (defogger, wipers, headlights, blower). Refer to Circuit Testing in Wiring Systems.

Is the voltage as specified?

10-14 V

Go to Step 5

Go to Step 14

5
  1. Connect the SDM connector.
  2. Turn ON the Ignition, with the engine OFF and wait at least 60 seconds.
  3. Operate the electrical system (defogger, wipers, headlights, blower) and check that the Air Bag indicator goes OFF

Is the Air Bag Indicator OFF?

 

Go to Step 6

Go to Step 14

6
  1. Turn OFF the ignition.
  2. Disconnect the negative battery cable and wait at least 90 seconds.
  3. Connect the negative battery cable and wait at least 2 seconds.
  4. Turn ON the ignition, with the engine OFF and wait at least 20 seconds.
  5. Select the SIR clear DTCs function on the scan tool.
  6. Turn OFF the ignition and wait at least 20 seconds.
  7. Turn ON the ignition, with the engine OFF and wait at least 20 seconds.
  8. Select the SIR display DTCs function on the scan tool.

Does the scan tool display any DTCs?

 

Go to Step 12

Go to Step 7

7
  1. Disconnect the instrument panel cluster connector.
  2. Turn the Ignition ON, engine OFF and wait at least 6 seconds.
  3. Measure the Air Bag Indicator Control circuit voltage at instrument panel cluster connector. Refer to Circuit Testing in Wiring Systems.

Is the voltage as specified?

Above 8 V

Go to Step 8

Go to Step 9

8

Replace the instrument panel cluster assembly. Refer to Instrument Cluster Replacement .

Did you complete the replacement?

 

Go to Step 15

 

9
  1. Turn OFF the ignition.
  2. Disconnect the SDM connector.
  3. Measure the resistance of the Air Bag Indicator Control circuit to ground. Refer to Circuit Testing in Wiring Systems.

Is the resistance as specified?

1 Mohms or greater

Go to Step 10

Go to Step 11

10
  1. Turn OFF the ignition.
  2. Disconnect the SDM connector.
  3. Disconnect the instrument panel cluster connector.
  4. Measure the resistance of the Air Bag Indicator Control circuit. Refer to Circuit Testing in Wiring Systems.

Is the resistance as specified?

Below 1 ohms

Go to Step 12

Go to Step 13

11

Repair short to ground in Air Bag Indicator Control Circuit. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

 

Go to Step 15

--

12

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

Did you complete the replacement?

 

Go to Step 15

--

13

Repair open or high resistance in Air Bag Indicator Control Circuit. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

 

Go to Step 15

--

14

Repair or replace harness between battery and SDM, and charging system. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

 

Go to Step 15

--

15

Operate the system in order to verify the repair.

Did you correct the condition?

 

System OK

Go to Step 2