GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Spark 🢒 Restraints 🢒 SIR 🢒 DTC 004

Circuit Description

When the ignition switch is turned ON, the sensing and diagnostic module (SDM) will perform tests to diagnose any malfunctions within itself.

After passing these tests, the SDM will check the driver air bag module firing circuit. The SDM allows a very small amount of current to flow through the circuit. The SDM monitors voltage during this check.

Conditions for Setting the DTC

The firing circuit is shorted to voltage.

Step

Action

Values

Yes

No

Caution: Refer to Battery Disconnect Caution in the Preface section.

 

1

Visually inspect the supplemental inflatable restraints (SIR) harness for damage.

Is there any visible damage to the SIR harness?

--

Go to Step 2

Go to Step 3

2
  1. Replace the SIR wiring harness.
  2. Reconnect the negative battery cable.

Is the repair complete?

--

Go to Diagnostic System Check - SIR

--

3
  1. Remove the driver air bag module.
  2. Place the driver air bag module in a secure position with the panel side facing upward.
  3. Disconnect the electrical connector at the SDM.

    4. The shorting bar at the disconnected SDM connector will create a complete circuit between the wires from the driver air bag module.

  4. Use a multimeter to check the voltage at one of the terminals on the wiring harness connector for the driver air bag module. Refer to Diagnostic Illustration 6 in SIR Diagnostic Illustrations .

Is the voltage greater than the specified value?

0 V

Go to Step 6

Go to Step 4

4
  1. Replace the SDM.
  2. Reconnect the negative battery cable.
  3. Set the scan tool for CODE ERASE.
  4. Perform the diagnostic system check.

Does DTC 004 still show as a current fault?

--

Go to Step 5

System OK

5
  1. Replace the driver air bag module.
  2. Reconnect the negative battery cable.

Is the repair complete?

--

Go to Diagnostic System Check - SIR

--

6
  1. Disconnect the coil spring wiring harness at the lower steering column.

    2. The shorting bar at the disconnected SDM connector will create a complete circuit between the wires from the coil spring connector.

  2. Using a multimeter, check the voltage at one of the terminals on the SDM side of the coil spring connector. Refer to Diagnostic Illustration 7 in SIR Diagnostic Illustrations .

Did the voltmeter indicate the specified value?

0 V

Go to Step 7

Go to Step 2

7
  1. Replace the coil spring.
  2. Reconnect the negative battery cable.

Is the repair complete?

--

Go to Diagnostic System Check - SIR

--