GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2007 🢒 Vibe - FWD 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 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 sensing and diagnostic module (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 .

Test Description

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

  1. Tests the ignition positive voltage circuit voltage.

    2.

  2. Tests the SDM ground circuits for open or high resistance.

    3.

  3. Tests the AIR BAG indicator control circuit voltage.

    4.

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

    5.

  5. 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 the Diagnostic System Check - Vehicle?

 

Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Turn OFF the ignition.
  2. Disconnect the sensing and diagnostic module (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 .

Did you find and correct the condition?

 

Go to Step 14

Go to Step 3

3
  1. Disconnect the SDM connector.
  2. Turn the ignition ON, with the engine OFF and wait at least 2 seconds.
  3. Measure the voltage of the ignition positive voltage circuit. Refer to Circuit Testing .

Is the voltage as specified?

10-14 V

Go to Step 4

Go to Step 13

4

Measure the resistance of the SDM ground circuits to known good ground. Refer to Circuit Testing .

Is the resistance as specified?

Below 1 ohms

Go to Step 5

Go to Step 12

5

  1. Disconnect the instrument panel cluster (IPC) connector.
  2. Turn the ignition ON, engine OFF and wait at least 6 seconds.
  3. Measure the air bag indicator control circuit voltage at IPC connector. Refer to Circuit Testing .

Is the voltage as specified?

Above 8 V

Go to Step 6

Go to Step 7

6

Replace the IPC assembly. Refer to Instrument Cluster Replacement .

Did you complete the replacement?

 

Go to Step 14

 

7

  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 .

Is the resistance as specified?

1 Mohms or greater

Go to Step 8

Go to Step 9

8

  1. Turn OFF the ignition.
  2. Disconnect the SDM connector.
  3. Disconnect the IPC connector.
  4. Measure the resistance of the air bag indicator control circuit. Refer to Circuit Testing .

Is the resistance as specified?

Below 1 ohms

Go to Step 10

Go to Step 11

9

Repair short to ground in air bag indicator control circuit. Refer to Wiring Repairs .

Did you find and correct the condition?

 

Go to Step 14

--

10

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

Did you complete the replacement?

 

Go to Step 14

--

11

Repair open or high resistance in air bag indicator control circuit. Refer to Wiring Repairs .

Did you find and correct the condition?

 

Go to Step 14

--

12

Repair open or high resistance in SDM ground circuits. Refer to Wiring Repairs .

Did you find and correct the condition?

 

Go to Step 14

--

13

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

Did you find and correct the condition?

 

Go to Step 14

--

14

Operate the system in order to verify the repair.

Did you correct the condition?

 

System OK

Go to Step 2