Hummer H2. Manual - part 2031

DTC B1001 

Circuit Description 

When the ignition is turned ON, the inflatable restraint sensing and diagnostic module (SDM) compares the 
restraints ID stored in the SDM to the restraints ID stored in the body control module (BCM). The restraints ID 
being compared contains the last four digits of the SDM part number. For more detailed information concerning 
Class 2 serial data lines, refer to Data Link Communications Description and Operation in Data Link 
Communications. 

Conditions for Running the DTC 

Ignition 1 voltage is within the normal operating voltage range. 

Action Taken When the DTC Sets 

z

The SDM disables all AIR BAG deployments.  

z

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.  

z

You issue a scan tool CLEAR DTCs command.  

z

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

Diagnostic Aids 

DTC B1001 is an indication that the restraints ID stored in both the BCM and SDM do not match. If either the 
BCM or PCM were replaced, the replacement modules need to be reprogrammed for proper operation. In 
addition, if the BCM or SDM were replaced, the vehicle theft deterrent (VTD) system will also need to be 

Does the DTC reset?

Step 

12

System OK

12

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 

13

-

13

1. Turn ON the ignition, with the engine OFF  

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.  

Does the DTC reset?

Go to 

Step 

2

System OK

 

2004 Hummer H2 

2004 RESTRAINTS SIR - Hummer H2

  

reprogrammed. 

Test Description 

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

2: This step checks to see if the correct VIN is programmed in the PCM.  

3: This step explains the proper steps to perform after a PCM has been replaced in order for the PCM to 
operate properly.  

5: This step explains the proper steps to perform after a BCM has been replaced in order for the BCM to 
operate properly.  

8: This step explains how to properly program the vehicle theft deterrent (VTD) system.  

DTC B1001 

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. With a scan tool, verify that the PCM is programmed with the 

correct VIN by comparing the VIN that is stored in the PCM to 
the VIN plate of the vehicle.  

Is the PCM programmed with the correct VIN?

Go to 

Step 4

Go to Step 3

3

With a scan tool and/or techline machine, program the correct VIN 
into the PCM. Refer to PCM programming in Engine Controls. 
Did you complete the programming procedure?

Go to 

Step 9

-

4

Was the BCM replaced?

Go to 

Step 5

Go to Step 6

5

Program the BCM in order for the BCM to learn the restraints ID from 
the SDM. Refer to Body Control Module (BCM) 
Programming/RPO Configuration in Body Control System. 
Did you complete the programming procedures?

Go to 

Step 8

-

6

Was the SDM replaced?

Go to 

Step 8

Go to Step 7

7

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

Go to 

Step 8

-

IMPORTANT:

Use the scan tool to perform the VTD relearn. Do not use the 30 
minute manual learn procedure.

 

2004 Hummer H2 

2004 RESTRAINTS SIR - Hummer H2

  

SYMPTOMS - SIR 

Visual/Physical Inspection 

z

Inspect for aftermarket devices which could affect the operation of the SIR system. Refer to Checking 
Aftermarket Accessories in Wiring Systems.  

z

Inspect the easily accessible or visible system components for obvious damage or conditions which could 
cause the symptom.  

Intermittent 

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for 
Intermittent Conditions and Poor Connections in Wiring Systems. 

Symptom List 

Refer to Air Bag Indicator Circuit Malfunction in order to diagnose the symptom. 

AIR BAG INDICATOR CIRCUIT MALFUNCTION 

Circuit Description 

The AIR BAG warning lamp is controlled by the inflatable restraint sensing and diagnostic module (SDM) via 
Class 2 serial data. When the ignition switch is first turned to the RUN position, the SDM performs tests to 

8

Reprogram the vehicle theft deterrent (VTD) system. Refer to 
Programming Theft Deterrent System Components in Theft 
Deterrent.Did you complete the reprogramming procedure?

Go to 

Step 9

-

9

1. Verify that all components, connectors, and CPAs are properly 

mounted.  

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 supporting text.  

Does the DTC reset?

Go to 

Step 2

System OK

IMPORTANT: The following steps must be completed before using the Symptom Tables. 

1. Perform the Diagnostic System Check - SIR before using the Symptom 

Tables in order to verify that all of the following are true: 

z

There are no DTCs set.  

z

The control module(s) can communicate via the serial data link.  

2. Review the system operation in order to familiarize yourself with the 

system functions. Refer to SIR System Description and Operation .  

 

2004 Hummer H2 

2004 RESTRAINTS SIR - Hummer H2

  

diagnose critical malfunctions within itself. The SDM then commands the AIR BAG warning lamp OFF after it 
has flashed seven times. 

Diagnostic Aids 

z

If Ignition 1 voltage is outside of the normal operating voltage range (9-16 volts), the AIR BAG warning 
lamp will come ON solid with no DTCs set.  

z

The loss of serial data communication between the inflatable restraint sensing and diagnostic module 
(SDM) and the instrument panel cluster (IPC), will cause the AIR BAG warning lamp to come ON solid. 
Refer to DTC U1001-U1254 in Data Link Communications.  

Test Description 

The number(s) below refer to the step number(s) on the diagnostic table. 

3: This step checks to see if the AIR BAG warning lamp flashes seven times when the ignition switch is 
first turned to the RUN position.  

4: This step checks to see if DTC U1088 is present in the instrument panel cluster (IPC).  

5: This step checks to see if the AIR BAG warning lamp can be commanded ON.  

6: This step checks to see if ignition 1 voltage to the SDM is more than 9 V.  

7: This step determines if ignition 1 voltage to the SDM is more than 16 V or if there is a malfunctioning 
SDM.  

8: This step inspects the SDM wiring harness connector for corrosion or damage.  

10: Tests for an open or high resistance in the ignition 1 voltage circuit between the SDM and the SIR 
Fuse.  

12: Tests for an open or high resistance in the ignition 1 voltage circuit to the SIR Fuse.  

14: Tests for an open or high resistance in the SDM ground circuit or if there is a malfunctioning SDM.  

Air Bag Indicator Circuit Malfunction 

Step

Action

Value

(s)

Yes

No

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

1

Did you perform the SIR Diagnostic System 
Check?

-

Go to Step 2

Go to Diagnostic 

System Check - SIR

2

Did you perform the Instrument Cluster 
Diagnostic System Check?

-

Go to Step 3

Go to Diagnostic 

System Check - 

Instrument Cluster 

in Instrument Panel, 

Gauges and Console

3

1. Turn OFF the ignition.  

2. Observe the AIR BAG warning lamp 

while turning the ignition switch to the 

-

 

2004 Hummer H2 

2004 RESTRAINTS SIR - Hummer H2