Adam F123 I've been commenting on this forum a long time now, however it seems old "resurrected" posts such as this, tend to have a poor response.

In the UK there are very few Hummers (55'ish) compared to US, so most of my contributions are based on researching service manuals, this forum, YT and experiences on my own truck.

This forum is undoubtedly the place to be, members here are committed to helping others where possible, sometimes successfully, but sadly sometimes never get see the final (valuable) feedback that says "problem fixed!"

"Sad" because it can take many hours of research to come-up possible answers and never knowing the outcome can be demoralizing, like it's time was wasted. Perhaps members simply move on to the next issue, maybe they're dealers looking for quick fixes, who knows, but fortunately there are many that do respond, which is great!

So to help you specifically, any information, pictures of your module and it's connectors, DTC's, history etc would be useful .....

 

Thanks. I attached a pic of the module with part numbers. DTC's are U1000 and U1088 Hummer sat for 2 years or so, and we've been having multiple electrical issues. I think a lot of them came from the leaking windshield. Floorboards were wet. Dash got wet. We pulled the airbag ECU out and it was corroded on the outside, but the pins and connector looked OK.

 

Indeed the earlier problem seems identical.

Earlier I said "The module seems well sealed ("potted") so its unlikely that water has ingressed inside." however I'm not entirely sure this is true for the following reasons:-

This photo, taken from a repair website, suggests the module is far from being hermetically sealed (as its accessible) so it's reasonable to assume being inside the vehicle, GM didn't need it to be. If it does have an IP protected connector the module electronics could be OK but the DTC suggests otherwise.

Sealed modules tend to be filled with rubber which the above isn't (if it's the same unit)

Any water or damp getting inside could have caused corrosion leading to open or shorted tracks.

If possible, I'd be tempted to take a look inside and see if it looks pristine, like the one pictured above, if so it might be repairable. If you do open it up please post some pics of both PCB sides, these may help, you never know.

Never seen one up close, so it's pure conjecture on my part.