Hummer H2. Manual - part 2027

DTC B0022, B0024, OR B0026 

Circuit Description 

The driver deployment loop consists of a inflatable restraint steering wheel module, the inflatable restraint 
steering wheel module coil, steering wheel module high and steering wheel module low circuits. There is a 
shorting bar used within the steering wheel module coil connector which will short together both steering wheel 
module high circuit and steering wheel module low circuit 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 inflatable restraint sensing and diagnostic module (SDM) will allow current to flow through the deployment 
loop in order to deploy the 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 diagnostic trouble code (DTC) will be stored in memory. 

Conditions for Running the DTC 

Ignition 1 voltage is within the normal operating voltage range. 

Conditions for Setting the DTC 

z

DTC B0022 will set when the steering wheel module deployment loop resistance is less than 1.3 ohms for 
500 milliseconds.  

z

DTC B0024 will set when one of the following conditions occur: 

{

Steering wheel module high and/or low circuits is short to ground or short to voltage for 500 
milliseconds.  

{

Steering wheel module high circuit is less than 2.4 volts and steering wheel module deployment 
loop resistance is less than 6 ohms for 500 milliseconds.  

z

DTC B0026 will set when one of the following conditions occurs: 

{

Steering wheel module high circuit is less than 2.4 volts and the steering wheel module deployment 
loop is more than 6 ohms for 500 milliseconds.  

{

Steering wheel module deployment loop resistance is more than 4.8 ohms for 500 milliseconds.  

Action Taken When the DTC Sets 

The SDM commands the AIR BAG indicator ON via Class 2 serial data. 

Conditions for Clearing the DTC 

z

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

9

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

 

2004 Hummer H2 

2004 RESTRAINTS SIR - Hummer H2

  

used.  

z

A history DTC will clear once 255 malfunction free ignition cycles have occurred.  

Diagnostic Aids 

The following are possible causes of the malfunction: 

z

A short between the steering wheel module high and low circuits.  

z

An open or a high resistance in the steering wheel module high or low circuits.  

z

A short to ground or a short to voltage in the steering wheel module high or low circuits.  

z

The steering wheel module coil connector  

z

The SDM connector  

z

A malfunctioning steering wheel module  

z

A malfunctioning steering wheel module coil  

z

A malfunctioning SDM  

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. 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. 

5: Tests to see if the malfunction is caused by the steering wheel module or by the steering wheel module 
coil.  

7: Tests to see what DTCs are present. If DTC B0022 is present, test the steering wheel module for a 
short between high and low circuits. If DTC B0024 is present, test the steering wheel module high and 
low circuits for an open and for high resistance. If DTC B0026 is present, test the steering wheel module 
high and low circuits for an open and for high resistance.  

DTC B0022, B0024, or B0026 

Step

Action

Yes

No

Schematic Reference:SIR Schematics 
Connector End View Reference:SIR Connector End Views and Inline Harness Connector End 
Views in Wiring Systems.

1

Did you perform A Diagnostic System Check - SIR?

Go to 

Step 2

Go to 

Diagnostic 

System Check -

SIR

1. Turn OFF the ignition.  

2. Disconnect the steering wheel module coil in-line connector. Refer 

 

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2

to Inflatable Restraint Steering Wheel Module Coil 
Replacement (Coil) .  

3. Inspect the component and harness sides of the in-line connector for 

the steering wheel module coil for damage or corrosion that may 
cause the malfunction. Refer to Testing for Intermittent 
Conditions and Poor Connections and Connector Repairs in 
Wiring Systems.  

Does connector exhibits any signs of damage or corrosion?

Go to 

Step 3

Go to Step 4

3

1. If the in-line connector for the steering wheel module coil is 

damaged, the steering wheel module coil must be replaced. Refer to 
Inflatable Restraint Steering Wheel Module Coil Replacement 
(Coil) .  

2. If the wiring harness side of steering wheel module coil in-line 

connector is damaged, replace the harness side of the connector. 
Refer to Connector Repairs in Wiring Systems.  

Did you complete the repair?

Go to 

Step 

11

-

4

1. Use the J 38715-100 adapter to connect the J 38715-A SIR 

Driver/Passenger Load Tool to the harness side of the steering 
wheel module coil in-line connector. See Special Tools and 
Equipment .  

2. Turn ON the ignition, with the engine OFF.  

3. Use the scan tool to request SIR DTCs displayed.  

Does the scan tool indicate that DTC B0022, B0024, or B0026 are 
current?

Go to 

Step 6

Go to Step 5

5

1. Turn OFF the ignition.  

2. Disconnect and remove both the J 38715-A . See Special Tools and 

Equipment .  

3. Connect the steering wheel module coil in-line connector.  

4. Remove the steering wheel module. Refer to Inflatable Restraint 

Steering Wheel Module Replacement .  

5. Use the J 38715-30A adapter to connect the J 38715-A to the upper 

steering wheel module coil connector on top of the steering column. 
See Special Tools and Equipment .  

6. Turn ON the ignition, with the engine OFF.  

7. Use the scan tool to request SIR DTCs displayed.  

Does the scan tool indicate that DTC B0022, B0024, or B0026 are 
current?

Go to 

Step 9

Go to Step 8

1. Turn OFF the ignition.  

 

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6

2. Disconnect and remove both the J 38715-A and adapter. See 

Special Tools and Equipment .  

3. Disconnect the inflatable restraint sensing and diagnostic module 

(SDM) connector. Refer to Inflatable Restraint Sensing and 
Diagnostic Module Replacement .  

4. Inspect the SDM connector for damage or corrosion that may cause 

a malfunction in the steering wheel module high and/or low circuits. 
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 

11

Go to Step 7

7

1. If DTC B0022 is present, test the steering wheel module for a short 

between the high and low circuits.  

2. If DTC B0024 is present, test the steering wheel module high and 

low circuits for a short to ground and for a short to voltage.  

3. If DTC B0026 is present, test the steering wheel module high and 

low circuits for an open and for high resistance.  

4. All the above conditions refer to Circuit Testing and Wiring 

Repairs in Wiring Systems.  

Did you find and correct the condition?

Go to 

Step 

11

Go to Step 10

8

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 

11

-

9

1. Turn OFF the ignition.  

2. Replace the steering wheel module coil. Refer to Inflatable 

Restraint Steering Wheel Module Coil Replacement (Coil) .  

Did you complete the replacement?

Go to 

Step 

11

-

10

1. Turn OFF the ignition.  

2. Replace the SDM. Refer to Inflatable Restraint Sensing and 

Diagnostic Module Replacement .  

Did you complete the replacement?

Go to 

Step 

11

-

11

1. Connect all SIR components.  

2. Turn ON the ignition, with the engine OFF.  

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.  

 

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