This may be a start....

 

Sorry 256x8 Bit EEPROM so only 256 bytes of memory, so not big.

 

Might be similar to this:-

 

the milage is not encrypted and human readable. i do not recall what offset the data is located at. but i am sure you can query the data dump.

 

on 03 and some 04 it lives there on the right side of the PRND321 screen and above the odometer
on 05 it changes location a bit away from the 2 screens if i recall nearer to the fuel oil / gauges

 

Looking at your old posts I see you created an Air Suspension Module. Wondering why you never tackled this odometer issue in the cluster?

Old Post (https://www.hummerforums.com/forum/h...t=41628&page=1)

 

here you can see some of the human readable data

 

I found several videos from a Youtuber named Jack Myers. He shows the complete process of removing and adding a new eeprom on the cluster along with programming it

 

TBH never really considered, or got into, the odometer topic for various reasons, however I did consider reverse engineering the IPC mainly to address some of the many reliability issues people had with it. If I could get my hands on an old one I would, ditto for the BCM (scrap parts not easy to acquire in the UK)

There's so many items of interest in the Hummer, many involving electronics, mechanics and software, the latter being one I've yet to touch on. Pretty much deal with components as they are encountered, for example :-


Boring for many, but challenging nonetheless, it's all aimed at understanding the issues and helping folks keep their stuff going.

Coming back to the odometer, having now seen the work out there, no doubt one could to write a utility (Python maybe) to read/set the mileage plus any other parameters, there must be people who do this.......

I can see it may pose a legal question after upgrading unless zero miles was the new staring point, not sure if physically transferring the original EEPROM would get around this, it's not really my area.

 

Here is a 6 second click of the Hummer H2 Digital Display. Not the final rendition but you can see display in action. Let me know what your thoughts are!