Hi Forum friends!
I'm working on my Bro-n-laws 2003 Hummer H2. 275,xxx miles. abs & brake light illuminated on dash panel. will not shift to 4hi or 4lo, will not shift xfer case to neutral. has U1000 Class 2 Data Link Malfunction code for 1 powertrain code, 1 anti-lock brake system code and 1 airbag code. i have rebuilt the abs pump and reinstalled, cleaned the 4wd switch in dash, replaced front wheel speed sensors and removed, cleaned, reinstalled rear wheel speed sensors, checked for power at xfer case encoder motor harness connector and have power and replaced the xfer case encoder motor. still have same codes, lights etc. I'm thinking i have a bad TCCModule or something in ECM
Kindly asking for thoughts and input...

 

Scan ALL modules and post the codes.

 

When he brought to my house, it sat a few days before i could get to it. The battery was down, so i connected my trickle charger and let it build up. it seems fine now, starts, etc. and These are the codes I pulled off the vehicle.
4 powertrain codes:
C0306 - Motor A/B cicuit malfunction
C0327 - Encoder circuit malfunction
B2725 - ATC mode switch circuit malfunction
U1000 - Class 2 Data Link malfunction

3 Anti-Lock Brake system codes:
U1300 - Class 2 Data Link Low
U1000 - Class 2 Data Link malfunction
U1064 - Lost communications with Body Multiple Control System

2 Airbag Codes:
​​​​​​U1000 - Class 2 Data Link malfunction
​​​​​​U1064 - Lost communications with Body Multiple Control System

1 Body Control Module Code:
​​​​​​U1000 - Class 2 Data Link malfunction

1 Vehicle Communication Interface Module Code:
B2470 - Cellular phone antenna circuit malfunction

1 HVAC Code:
U1064 - Lost communications with Body Multiple Control System

1 Door Module Code:
​​​​​​U1064 - Lost communications with Body Multiple Control System

1 Shared Address Module Code:
​​​​​​U1064 - Lost communications with Body Multiple Control System

2 Shared Address Module Codes:
​​​​​U1000 - Class 2 Data Link malfunction
​​​​​​U1064 - Lost communications with Body Multiple Control System

 

My apologies for the delay in posting these. The codes are as follows:

4 Powertrain Codes:
C0306 Motor A/B circuit malfunction
C0327 Encoder circuit malfunction
B2725 ATC mode switch circuit malfunction
U1000 Class 2 Data Link Malfunction

3 Anti-Lock Brake System Codes:
U1300 Class 2 Data Link Low
U1000 Class 2 Data Link Malfunction
U1064 Lost communications with Body Multiple Control System

2 Airbag Codes:
​​​​​​U1000 Class 2 Data Link Malfunction
U1064 Lost communications with Body Multiple Control System

1 Body Control Module Code:
​​​​​U1000 Class 2 Data Link Malfunction

1 Vehicle communication Interface Module Code:
B2470 Cellular phone antenna circuit malfunction

1 HVAC Code:
U1064 Lost communications with Body Multiple Control System

1 Door Module code:
​​​​​​U1064 Lost communications with Body Multiple Control System

1 Shared Address Module Code:
U1064 Lost communications with Body Multiple Control System

2 Shared Address Module Codes:
​​​​​​U1000 Class 2 Data Link Malfunction
U1064 Lost communications with Body Multiple Control System

i'm not worried about the cellular phone antenna B2470 code, however I'm thinking that the 4wd issue is separate and can be fixed with a new switch in dash and the remainder are Body Control Module issues.
I'm looking forward to any input from H2 gurus that have encountered this before...

​​​​​​​Thank you to all of you in advance!

 

Agreed. You will need to scan your ABS codes which needs to be done with a more advanced scanner tool. It could be something as small as a wheel sensor.

 

Thank you for the reply. the front wheel sensors have been replaced. the rear wheel speed sensors are removed and inspected, they looked as though they've been recently replaced. I've read that if there is excess slack in the hubs that it could be a possible culprit and I think about that since this H2 has 275,xxx miles indicated.

 

Had a scan done by a neighbor and he came up with the following codes

4 powertrain codes
C0306 Motor A/B circuit malfunction
C0327 Encoder circuit malfunction
B2725 ATC mode switch circuit malfunction
U1000 Class 2 Data Link Malfunction

3 Anti-Lock Brake System Codes
U1300 Data Link Low
​​​​​​U1000 Class 2 Data Link Malfunction
U1064 Lost communications with Body Multiple Control System

2 Airbag Codes
​​​​​​U1000 Class 2 Data Link Malfunction
​​​​​​U1064 Lost communications with Body Multiple Control System

1 Body Control Module Code
U1000 Class 2 Data Link Malfunction

1 Vehicle communication Interface Module Code
B2470 Cellular phone antenna circuit malfunction

1 HVAC Code​​​​​​
U1064 Lost communications with Body Multiple Control System

1 Door Module Code
​​​​​U1064 Lost communications with Body Multiple Control System

1 Shared Address Module Code
​​​​​​​​​​​​U1064 Lost communications with Body Multiple Control System

2 Shared Address Module Codes
​​​​​​U1000 Class 2 Data Link Malfunction
​​​​​​U1064 Lost communications with Body Multiple Control System

Seeing these codes leads me to think that I have a Body Control Module or yaw sensor causing problems along with either a bad switch, xfer case control module or xfer case sensor.
I've checked for dampness or signs of corrosion on the module under the drivers seat and it is amazingly clean with no signs of corrosion outside or at the connector.

​​​​​​​

 

Desperately seeking answers without posting the codes? Just keep throwing parts at it.

 

I've replied with the codes earlier and I apologize since i must not have done the reply correctly, of course I'll add that I don't claim to be a keyboard warrior either.

so, I'll try to send the DTC list again without throwing more parts at it...

4 Powertrain Codes
C0306 Motor A/B circuit malfunction
C0327 Encoder circuit malfunction
B2725 ATC mode switch circuit malfunction
U1000 Class 2 Data Link Malfunction

3 Anti-Lock Brake System Codes
U1300 Class 2 Data Link Low
​​​​​​U1000 Class 2 Data Link Malfunction
U1064 Lost communications with Body Multiple Control System

2 Airbag Codes
​​​​​​U1000 Class 2 Data Link Malfunction
U1064 Lost communications with Body Multiple Control System

1 Body Control Module Code
U1000 Class 2 Data Link Malfunction

1 Vehicle Communication Interface Module Code
B2470 Cellular phone antenna circuit malfunction

1 HVAC Code
U1064 Lost communications with Body Multiple Control System

1 Door Module Code
U1064 Lost communications with Body Multiple Control System

1 Shared Address Module Code
U1064 Lost communications with Body Multiple Control System

2 Shared Address Module Codes
U1000 Class 2 Data Link Malfunction
U1064 Lost communications with Body Multiple Control System

That's what a friend pulled off with his scan tool. I'm now reading up on them... and reading the repeats just to make sure I understand them. Jus kiddin.

I'm much more comfortable working on my '62 corvette... no modules! no computers!

 

I'll be the first to admit I'm really not a keyboard warrior. that's probably why i enjoy working on my old Harley and '62 corvette more than a hummer.
I have sent the codes that were pulled on a couple of other replies and damned if I know where their at!
So, one more attempt without throwing anymore parts at it...

4 Powertrain Codes
C0306 Motor A/B circuit malfunction
C0327 Encoder circuit malfunction
B2725 ATC mode switch circuit malfunction
U1000 Class 2 Data Link Malfunction

3 Anti-Lock Brake System Codes
U1300 Class 2 Data Link Low
U1000 Class 2 Data Link Malfunction
U1064 Lost communications with Body Multiple Control System

2 Airbag Codes
U1000 Class 2 Data Link Malfunction
U1064 Lost communications with Body Multiple Control System

1 Body Control Module Code
U1000 Class 2 Data Link Malfunction

1Vehicle communication Interface Module Code
B2470 Cellular phone antenna circuit malfunction

1HVAC Code
U1064 Lost communications with Body Multiple Control System

1 Door Module Code
U1064 Lost communications with Body Multiple Control System

1 Shared Address Module Code
U1064 Lost communications with Body Multiple Control System

2 Shared Address Module Codes
U1000 Class 2 Data Link Malfunction
U1064 Lost communications with Body Multiple Control System

I hope this post shows up and doesn't give the message that it will appear once it's blessed by an administrator...