GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The steering wheel module deployment loop consists of a dual stage inflatable restraint steering wheel module, an inflatable restraint steering wheel module coil, the steering wheel module - high and steering wheel module - low circuits. There are 2 shorting bar used in the inflatable restraint steering wheel module and the inflatable restraint steering wheel module coil connectors which will short together the steering wheel module - high and steering wheel module - low circuits when the connector is disconnected, this will help to prevent unwanted deployment of the inflator module during servicing. During a frontal crash of sufficient force the sensing and diagnostic module (SDM) will allow current to flow through the deployment loop in order to deploy the inflatable restraint steering wheel module. The SDM performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity and for shorts to ground or voltage. If a malfunction is detected, a DTC will be stored.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC B1810 Driver Air Bag Deployment Loop Resistance Too Low Circuit 2
    • DTC B1811 Driver Air Bag Deployment Loop Resistance Too High Circuit 2
    • DTC B1812 Driver Air Bag Deployment Loop Short To Ground Circuit 2
    • DTC B1813 Driver Air Bag Deployment Loop Short To Battery Circuit 2

Conditions for Running the DTC

Ignition 1 voltage is within the normal operating voltage range.

Conditions for Setting the DTC

B1810

This DTC will set when the SDM detects a low resistance condition in the steering wheel module deployment loop.

B1811

This DTC will set when the SDM detects a high resistance condition in the steering wheel module deployment loop.

B1812

This DTC will set when the SDM detects a short to ground in the steering wheel module deployment loop.

B1813

This DTC will set when the SDM detects a short to voltage in the steering wheel module deployment loop.

Action Taken When the DTC Sets

The SDM commands the AIR BAG indicator ON.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

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:

    • A short between the steering wheel module - high and the steering wheel module - low circuits
    • An open or high resistance in the steering wheel module - high or the steering wheel module - low circuits
    • A short to ground in the steering wheel module - high or the steering wheel module - low circuits
    • A short to voltage in the steering wheel module - high or the steering wheel module - low circuits
    • A malfunctioning inflatable restraint steering wheel module
    • A malfunctioning inflatable restraint steering wheel module coil
    • 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. This step tests to see if the malfunction is caused by the inflatable restraint steering wheel module.

  2. This step tests to see if the malfunction is caused by the inflatable restraint steering wheel module coil.

  3. This step tests to see if the malfunction is caused by the inflatable restraint steering wheel module.

  4. This step tests to see if the malfunction is caused by the inflatable restraint steering wheel module coil.

  5. This step tests for a short between the steering wheel module high and steering wheel module low circuits.

Step

Action

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

Is DTC B1810, B1811, B1812 or B1813 set as a current DTC?

Go to Step 3

Go to Diagnostic Aids

3

  1. Turn OFF the ignition.
  2. Remove the steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .
  3. Inspect both the component and harness sides of the steering wheel module connector for damage or corrosion that may cause the malfunction. Refer to Testing for Intermittent Conditions and Poor Connections .

Does the connector exhibit any signs of damage or corrosion?

Go to Step 4

Go to Step 5

4

  1. If the component side of the steering wheel module connector is damaged, the steering wheel module must be replaced. Refer to Inflatable Restraint Steering Wheel Module Replacement .
  2. If the harness side of the steering wheel module connector is damaged, the steering wheel module coil must be replaced. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement .

Did you complete the replacement?

Go to Step 16

--

5

Is DTC B1811, B1812 or B1813 set as a current DTC?

Go to Step 7

Go to Step 6

6

Is DTC B1810 set as a current DTC?

Go to Step 9

--

7

  1. Connect a 3-amp fused jumper wire between the steering wheel module - high and the steering wheel module - low circuits on the harness side of the steering wheel module black connector.
  2. Turn ON the ignition, with the engine OFF.
  3. Use the scan tool in order to Clear the DTCs.
  4. With the scan tool, request the SIR DTC display.

Does the scan tool indicate that DTC B1811, DTC B1812, or DTC B1813 is current?

Go to Step 8

Go to Step 13

8

  1. Disconnect the lower steering wheel module coil connector.
  2. Connect a 3-amp fused jumper wire between the steering wheel module - high and the steering wheel module - low circuits on the harness side of the steering wheel module coil connector.
  3. Use the scan tool in order to Clear the DTCs.
  4. With the scan tool, request the SIR DTC display.

Does the scan tool indicate that DTC B1811, DTC B1812, or DTC B1813 is current?

Go to Step 11

Go to Step 14

9

  1. Turn ON the ignition, with the engine OFF.
  2. Use the scan tool in order to Clear the DTCs.
  3. With the scan tool, request the SIR DTC display.

Does the scan tool indicate that DTC B1810 is current?

Go to Step 10

Go to Step 13

10

  1. Disconnect the lower steering wheel module coil connector.
  2. Use the scan tool in order to Clear the DTCs.
  3. With the scan tool, request the SIR DTC display.

Does the scan tool indicate that DTC B1810 is current?

Go to Step 11

Go to Step 14

11

  1. Turn OFF the ignition.
  2. Disconnect the sensing and diagnostic module (SDM) connector.
  3. Inspect the SDM connector for damage or corrosion that may cause a malfunction between the steering wheel module - high and/or the steering wheel module - low circuits. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 16

Go to Step 12

12

  1. If DTC B1810 is present, test for a short between the steering wheel module - high and the steering wheel module - low circuits.
  2. If DTC B1811 is present, test the steering wheel module - high and the steering wheel module - low circuits for an open or high resistance.
  3. If DTC B1812 is present, test the steering wheel module - high and the steering wheel module - low circuits for a short to ground.
  4. If DTC B1813 is present, test the steering wheel module - high and the steering wheel module - low circuits for a short to voltage.
  5. For all of the above conditions, refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 16

Go to Step 15

13

  1. Turn OFF the ignition.
  2. Replace the steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .

Did you complete the replacement?

Go to Step 16

--

14

  1. Turn OFF the ignition.
  2. Replace the steering wheel module coil. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement .

Did you complete the replacement?

Go to Step 16

--

15

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

Did you complete the replacement?

Go to Step 16

--

16

  1. Reconnect all SIR components.
  2. Verify that all components, connectors, and connector position assurances (CPAs) are properly mounted.
  3. Use the scan tool in order to Clear the DTCs.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK