Hummer H2. Manual - part 185

DTC B1009 

Circuit Description 

The electrically erasable programmable read-only memory (EEPROM) check sum error detection is handled 
inside the control module. No external circuits are involved. 

Conditions for Running the DTC 

The module runs the program to detect an EEPROM checksum error after each wake-up. The only requirements 
are battery positive voltage and ground. This program runs even if the voltage is out of the valid operating 
range. 

Conditions for Setting the DTC 

The module retains an inverse copy of the digital value stored in certain blocks of memory in the EEPROM. 
The module then reads the information from those certain blocks and adds the stored inverse value to the 
current value. If they do not equal 0, the module sets the DTC. 

Action Taken When the DTC Sets 

The module reverts to base operation values programed for those blocks of data that have failed the check sum 
test. The blocks of data that have not failed the check sum test are not affected. 

Conditions for Clearing the DTC 

z

A current DTC clears when the malfunction is no longer present.  

z

A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat 
of the malfunction.  

Diagnostic Aids 

z

This DTC may be stored as a history DTC without affecting the operation of the module. If stored only as 
a history DTC and not retrieved as a current DTC, do not replace the module.  

z

If this DTC is retrieved as both a current and history DTC, replace the module.  

3

Replace the control module setting the DTC as current. 
Refer to Control Module References .Did you 
complete the replacement?

Go to 

Step 4

-

4

1. Use the scan tool in order to clear the DTCs.  

2. 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 ACCESSORIES & EQUIPMENT Body Control System - Hummer H2

  

DTC B1009 

DTC B1397 

Circuit Description 

The body control module (BCM) provides an internal 12-volt reference for the steering wheel controls supply 
voltage circuit. 

Conditions for Running the DTC 

The voltage supplied to the BCM is in the range of 9-16 volts. 

Conditions for Setting the DTC 

The BCM senses a short to ground in the steering wheel controls supply voltage circuit, for more than 1 second.

Action Taken When the DTC Sets 

The BCM will disable the output for the rest of the ignition cycle. 

The steering wheel switches will not perform their function.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check for the 
system exhibiting the symptom?

Go to 

Step 2

Go to Control Module 

References for the applicable 

Diagnostic System Check

2

1. Install a scan tool.  

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

3. Retrieve DTCs.  

Is the DTC retrieved as a current DTC?

Go to 

Step 3

Go to Diagnostic Aids

3

Replace the control module setting the DTC as current. 
Refer to Control Module References .Did you 
complete the replacement?

IMPORTANT:

Perform the programming or setup procedure for the 
module if required.

Go to 

Step 4

-

4

1. Use the scan tool in order to clear the DTCs.  

2. 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 ACCESSORIES & EQUIPMENT Body Control System - Hummer H2

  

Conditions for Clearing the DTC 

z

A current DTC clears when the malfunction is no longer present.  

z

A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat 
of the malfunction.  

Diagnostic Aids 

An intermittent short to ground in the steering wheel controls supply voltage circuit will set the code. Inspect 
for loose or poor connections at all related components. Refer to Testing for Intermittent Conditions and 
Poor Connections in Wiring Systems. 

DTC B1397 

Step

Action

Yes

No

Schematic Reference:Radio/Audio System Schematics (non Class 2 Amplifier) or Radio/Audio 
System Schematics (Class 2 Amplifier) in Entertainment 
Connector End View Reference:Master Electrical Component List in Wiring Systems

1

Did you perform the diagnostic system check for the system exhibiting 
the symptom?

Go to 

Step 2

Go to Control 

Module 

References

2

1. Install a scan tool.  

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

3. Retrieve DTCs from body control module (BCM).  

Is the DTC set as current?

Go to 

Step 3

Go to Diagnostic 

Aids

3

1. Turn OFF the ignition.  

2. Disconnect the BCM connectors.  

3. Test the steering wheel controls supply voltage circuit at the 

BCM connector 1 for a short to ground.  

4. Refer to the following in Wiring Systems: 

z

Circuit Testing  

z

Wiring Repairs  

z

Testing for Intermittent Conditions and Poor 
Connections  

z

Connector Repairs  

Did you find and correct the condition?

Go to 

Step 6

Go to Step 4

4

Inspect for poor connections at the harness connectors of the BCM. 
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 6

Go to Step 5

IMPORTANT:

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Body Control System - Hummer H2

  

DTC B1440 

Circuit Description 

The body control module (BCM) is the power mode master responsible for sending ignition switch position 
information on the class 2 serial data link. The BCM monitors 3 discrete wires from the ignition switch contacts 
and the engine run flag (ERF) in order to determine the present power mode. The BCM communicates this 
power mode information to all class 2 modules on the class 2 serial data link. The following table represents 
correct BCM power mode data: 

Correct Ignition Switch Inputs 

Conditions for Running the DTC 

The only requirements are voltage and ground. 

Conditions for Setting the DTC 

One of the 3 monitored ignition switch circuits has malfunctioned. The DTC will set, if one of the following 
situations is present: 

Incorrect Ignition Switch Inputs 

5

Replace the BCM. Refer to Body Control Module Replacement .Did 
you complete the replacement?

Perform the module programming after replacement.

Go to 

Step 6

-

6

1. Reconnect all of the disconnected modules.  

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

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

Does the DTC reset?

Go to 

Step 2

System OK

Ignition Switch Position

BCM Input and Scan Tool Display

Ignition Accessory

Ignition 1

Ignition 0

OFF

Inactive

Off

Off

UNLOCK

Inactive

Off

On

ACC

Active

Off

On

ON

Active

On

On

START

Inactive

On

On

BCM Input and Scan Tool Display

Engine Running

Ignition Accessory

Ignition 1

Ignition 0

Inactive

On

Off

No

Active

Off

Off

No

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Body Control System - Hummer H2