BCM data link

[rcashman]

Quick question.
replaced the ECM, Had someone try to flash for me. Was told the BCM has a serial data fault. Does the key need to be programed before the security system will let them hook up to the bcm?

 

[Ron Nielson]

Introduction​

A new body control module (BCM) must be programmed with the latest operating software and vehicle calibrations. Ensure that the following conditions exist in order to prepare for BCM programming:

• The battery is fully charged.
• The ignition switch is in the ON position.
• The data link connector (DLC) is accessible.
• All disconnected modules and devices are connected.

Programming the BCM​

Note: The vehicle will not start and many other functions may not operate properly if a replacement BCM is not properly set up. The following procedures must be followed:

1. Programming the BCM
2. Learning the restraints ID

Note: After the procedure is completed, the personalization settings of the BCM are set to default settings. Inform the customer that the personalization must be set again.

Refer to Service Programming System (SPS) for more information.

Learning the Restraints ID​

Navigate on the scan tool to Vehicle Control Systems > Module Setup > Body Control Module > Setup SDM Primary Key in BCM, then follow the instructions on the screen.


Note: After programming, perform the following to avoid future misdiagnosis:

1. Turn the ignition OFF for 10 seconds.
2. Connect the scan tool to the data link connector.
3. Turn the ignition ON, with the engine OFF.
4. Use the scan tool in order to retrieve history DTCs from all modules.
5. Clear all history DTCs.

 

[rcashman]

Introduction​

A new body control module (BCM) must be programmed with the latest operating software and vehicle calibrations. Ensure that the following conditions exist in order to prepare for BCM programming:

• The battery is fully charged.
• The ignition switch is in the ON position.
• The data link connector (DLC) is accessible.
• All disconnected modules and devices are connected.

Programming the BCM​

Note: The vehicle will not start and many other functions may not operate properly if a replacement BCM is not properly set up. The following procedures must be followed:

1. Programming the BCM
2. Learning the restraints ID

Note: After the procedure is completed, the personalization settings of the BCM are set to default settings. Inform the customer that the personalization must be set again.

Refer to Service Programming System (SPS) for more information.

Learning the Restraints ID​

Navigate on the scan tool to Vehicle Control Systems > Module Setup > Body Control Module > Setup SDM Primary Key in BCM, then follow the instructions on the screen.


Note: After programming, perform the following to avoid future misdiagnosis:

1. Turn the ignition OFF for 10 seconds.
2. Connect the scan tool to the data link connector.
3. Turn the ignition ON, with the engine OFF.
4. Use the scan tool in order to retrieve history DTCs from all modules.
5. Clear all history DTCs.

Ron I was told there was a U0100 code as well. The BCM is the not new. It's the original. Only the ECM is new. Does your provided information still apply.

 

[rcashman]

Ron I was told there was a U0100 code as well. The BCM is the not new. It's the original. Only the ECM is new. Does your provided information still apply.

BTW I did have the aftermarket radio disconnected. Would that have caused the issue?

 

[2004LB7]

U0100 is more related to lost communication with the transmission control module.

Is the ECM new or blank slate? If so you may need to have a tech 2 or mdi load the full calibration on. Dealership can do this

Also, check your batteries. May need to put them on the charger before attempting to program to make sure they are fully charged

 

[Ron Nielson]

I didn't read your original post correctly. No, you don't need to program the BCM if it is not new. However, the ECM and BCM must communicate with each other via the GMLAN (or whichever com system (serial data) is used in your year truck). The first step is to make sure the BCM has power and ground. You probably need pro help to get this done because there can be multiple problems requiring a scanner and possibly more programming somewhere.

Do you have any other undisclosed codes?

 

[rcashman]

I didn't read your original post correctly. No, you don't need to program the BCM if it is not new. However, the ECM and BCM must communicate with each other via the GMLAN (or whichever com system (serial data) is used in your year truck). The first step is to make sure the BCM has power and ground. You probably need pro help to get this done because there can be multiple problems requiring a scanner and possibly more programming somewhere.

Do you have any other undisclosed codes?

No code. Brand new ecm. Just no bcm communication.

 

[2004LB7]

Maybe try disconnecting one module at a time to see if any are trying up the communication lines

 

[juddski88]

No code. Brand new ecm. Just no bcm communication.

What year truck?

 

[rcashman]

What year truck?

05 lly

 

[rcashman]

No code. Brand new ecm. Just no bcm communication.

Forgot to mention. Ths dash clusted also has check engine, abs, brake light on. DIC says service brake system and no prindle, It does still show PRND1. Also no speedo.

 

[Ron Nielson]

see the attachment.