Hummer H2. Manual - part 2030

DTC B0100, B0101, B0102, B0103, B0104, OR B0105 

Circuit Description 

The inflatable restraint electronic frontal sensor (EFS) utilizes a unidirectional 2-wire circuit. The EFS 
modulates current on the interface to send ID, State of Health, and deployment commands to the inflatable 
restraint sensing and diagnostic module (SDM). The SDM serves as a power source and a ground for the EFS. 
When the ignition is turned on and input power from the SDM is first detected, the EFS responds by performing 
internal diagnostics and sending an ID to the SDM. The SDM considers the ID to be valid if the response time 
is less than 5 seconds. The EFS continually communicates status messages to the SDM, which determines if a 

Does the scan tool indicate that the I/P module disable switch 
(active switch) is DISABLED?

Go to Step 

10

Go to Step 6

6

Test the I/P module disable switch signal circuit for a short. Refer 
to Circuit Testing and Wiring Repairs in Wiring Systems. 
Did you find and correct the condition?

Go to Step 

11

Go to Step 7

7

Test the I/P module suppression indicator control circuit for a 
short. Refer to Circuit Testing and Wiring Repairs in Wiring 
Systems. 
Did you find and correct the condition?

Go to Step 

11

Go to Step 8

8

1. Turn OFF the ignition.  

2. Disconnect the SDM connector. Refer to Inflatable 

Restraint Sensing and Diagnostic Module 
Replacement .  

3. Inspect the SDM connector for corrosion or damage. 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 9

9

Replace the SDM. Refer to Inflatable Restraint Sensing and 
Diagnostic Module Replacement . 
Did you complete the replacement?

Go to Step 

11

-

10

Replace the I/P module disable switch. Refer to Inflatable 
Restraint Instrument Panel (I/P) Module Disable Switch 
Replacement . 
Did you complete the replacement?

Go to Step 

11

-

11

1. Reconnect all SIR system components.  

2. Verify that all components, connectors and 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

 

2004 Hummer H2 

2004 RESTRAINTS SIR - Hummer H2

  

fault is present in the EFS circuit. When a fault is detected, the SDM may reset the EFS up to two times by 
removing and reapplying power to it. If the fault is still present, the SDM will set a diagnostic trouble code 
(DTC). 

Conditions for Running the DTC 

Ignition 1 Voltage is within the normal operating voltage range of 9-16 volts. 

Conditions for Setting the DTC 

z

DTC B0100 for the EFS-LF or B0103 for the EFS-RF will set when one of the following conditions 
occur: 

{

A valid ID message is not received within 5 seconds of the EFS being powered up.  

{

A status message is not received.  

{

The SDM has reset the EFS twice without detecting a valid ID message.  

z

DTC B0101 for the EFS-LF or B0104 for the EFS-RF will set when the SDM has received a NOK 
message from the EFS.  

z

DTC B0102 for the EFS-LF or B0105 for the EFS-RF will set when one of the following conditions 
occur: 

{

The SDM has received an ID message from the EFS which does not match the ID stored in the 
SDM memory.  

{

The SDM has reset the EFS twice without detecting the correct ID message.  

Action Taken When the DTC Sets 

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

Conditions for Clearing the DTC 

z

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

z

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

Diagnostic Aids 

The following are conditions that may cause the malfunction: 

z

A short to ground or voltage in the EFS circuit  

z

High or low resistance in the EFS circuit  

z

Improper EFS installed on vehicle  

Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and connectors may 
result in 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.

 

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Test Description 

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

7: Tests the EFS signal and EFS voltage circuits for an open or high resistance  

8: Tests between the EFS signal and EFS voltage circuits for continuity  

9: Tests the EFS signal and EFS voltage circuits for a short to voltage  

DTC B0100, B0101, B0102, B0103, B0104, or B0105 

Step

Action

Yes

No

Schematic Reference:SIR Schematics 
Connector End View Reference:SIR Connector End Views

1

Did you perform the Diagnostic System Check - SIR?

Go to 

Step 

2

Go to 

Diagnostic 

System Check 

- SIR

2

1. Install a scan tool.  

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 B0101, B0102, B0104, or B0105 is 
current?

Go to 

Step 

10

Go to Step 3

3

1. Turn OFF the ignition.  

2. If DTC B0100 is current, disconnect the inflatable restraint 

electronic frontal sensor (EFS) - LF connector. If DTC B0103 is 
current, disconnect the EFS-RF connector. The EFS is also known as 
the inflatable restraint front end discriminating sensor. Refer to 
Inflatable Restraint Front End Sensor Replacement .  

3. Inspect both the component and harness sides of the connector for 

damage or corrosion. Refer to Testing for Intermittent Conditions 
and Poor Connections in Wiring Systems.  

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 EFS connector is damaged, the EFS 

must be replaced. Refer to Inflatable Restraint Front End Sensor 
Replacement .  

2. If the harness side of the EFS 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

-

1. Turn OFF the ignition.  

2. Disconnect the Inflatable Restraint Sensing and Diagnostic Module 

 

2004 Hummer H2 

2004 RESTRAINTS SIR - Hummer H2

  

5

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

3. Inspect both the component and harness sides of the SDM connector 

for damage or corrosion. Refer to Testing for Intermittent 
Conditions and Poor Connections in Wiring Systems.  

Does the connector exhibit any signs of damage or corrosion?

Go to 

Step 

6

Go to Step 7

6

1. If the component side of the SDM connector is damaged, the SDM 

must be replaced. Refer to Inflatable Restraint Sensing and 
Diagnostic Module Replacement .  

2. If the harness side of the SDM 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

-

7

1. If DTC B0100 is current, disconnect the EFS-LF connector. If DTC 

B0103 is current, disconnect the EFS-RF connector.  

2. Test both the EFS signal and EFS voltage circuits for an open or 

high resistance between the SDM connector and the EFS connector. 
Refer to Circuit Testing and Wiring Repairs in Wiring Systems.  

Did you find and correct the condition?

Go to 

Step 

11

Go to Step 8

8

Test for continuity between the EFS signal circuit and the EFS voltage 
circuit on the SDM connector. Refer to Circuit Testing and Wiring 
Repairs in Wiring Systems. 
Did you find and correct the condition?

Go to 

Step 

11

Go to Step 9

9

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

2. Test both EFS signal and EFS voltage circuits for a short to voltage. 

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

10

1. Turn OFF the ignition.  

2. If DTC B0100, B0101, or B0102 was current replace the EFS-LF. If 

DTC B0103, B0104, or B0105 was current replace the EFS-RF. The 
EFS is also known as the inflatable restraint front end discriminating 
sensor. Refer to Inflatable Restraint Front End Sensor 
Replacement .  

Did you complete the replacement?

Go to 

Step 

11

-

11

1. Reconnect all SIR components.  

2. Use the scan tool in order to Clear the DTCs.  

3. Operate the vehicle within the Conditions for Running the DTC as 

specified in the text.  

Go to 

 

2004 Hummer H2 

2004 RESTRAINTS SIR - Hummer H2