OK, so I just got off the phone with Garrett Tuning. The guy said he could clone my BCM but he couldn't fix the wrong mileage displayed on the odometer, which right now is my biggest problem. Valley Cadillac put the original BCM back in the truck and everything functions normally except for the short range for the key fob. And somehow the mileage is showing as 131K instead of 30K. I have a used replacement BCM they tried and failed to put in. No one in town will touch this. Can you help me?

 

the video i posted has a link to his services that seem to specialize in your issue. maybe try contacting him?
https://gmflash.com/bcm-cloning-h3

 

Yeah, I called them (Spartan Auto Works), got a recording, left a voicemail and also sent them an email. We'll see what they say.

UPDATE

Well two days, one phone call and two emails later, not a peep out of Spartan Auto Works. So much for them. Does anyone have a suggestion on how I can get my mileage corrected?

What about these guys: https://www.upfix.com/product/hummer-h3-2005-2010-odometer-mileage-adjust-correction-service/

Or this: http://gmflash.com/bcm-cloning-h3

 

Another update - I finally did get a call back from Eric at Spartan Auto Works two days ago. They got 11" of snow in St. Louis, which apparently is a lot for them. Anyway he says the mileage in the original BCM is correct and all I need to do is send him the instrument cluster where he can reset it to zero. When I put it back in the truck, it will compare its value to that in the BCM and then copy the correct number to the display

And in another twist, I've been unlocking it with the physical key in the driver side door. Yesterday on a whim I tried the key fob and to my surprise it worked - from 20 feet away. And it's still working today. My theory is that the only thing wrong with this BCM is that moisture got in and was grounding the signal from the antenna. Now that moisture has finally evaporated on its own restoring the functionality. So I guess I won't even need that used BCM that caused all this bother by copying its excess mileage into my instrument cluster. Everything else in the original BCM works fine.

So now I have to pull the cluster to send it off. I assume it's the same as that video of someone pulling one from a Chevy Colorado - yank off the trim cover, undo four screws and unplug the connector.

 

I'm going to chime in on this because I am dealing with a very similar issue. To give you some backstory and where I am at today.

We had the same issue years ago with the leaking sunroof but it was over 8 years ago. Both key fobs started to not work periodically during the late summer/early fall in 2024. Replaced batteries and had the signal checked on them. All good. The key fobs would work 90%, then 80%, then 50%, then only in the vehicle to not at all. They haven't worked at all for over 5 months. I purchased a refurbished BCM directly from GM and took it to the local dealership before New Years. Big mistake...lesson learned. They had it for a couple of days. Says they never could get it to program and consulted with GM technical support. They also washed their hands of it and said to just get an aftermarket system. GM did swap out the BCM and gave me a new "refurbished" one. Luckily they didn't screw up the mileage.

So fast forward to just this week. On Monday I took our current BCM and the new "refurbished" one to a programmer in Virginia (screw the dealerships at this point). He physically inspected our current one and said it was in great condition but then he looked at the "refurbished" one and it was one of the worst he had even seen. He pointed to the water damage and corrosion on the board and where they had repaired some of the soldering. He did see where they had cleared the programming so at least they did that. He strongly advised not to utilize this BCM due to the condition of the board (he said wouldn't even consider putting this in his own vehicle because he had little confidence it would work correctly) so we didn't proceed with the programming. He didn't charge us for it at all.

So now today (Wednesday). We got some ice and snow here in NC. I go out and clean off the Hummer this evening. Run it for a bit and go out for a drive. I come back to the house, park up, and manually lock the door. I figured I would try the key fob for kicks and wouldn't you know, it works. It works outside, it works from inside the house. I've tried it different times, it works. So it got me thinking, is the ice and snow on the vehicle "solving" a grounding issue with the BCM? We have tried the fobs multiple times in the rain, heat, dry, and cold...all the same results of not working and that BCM had been in and out twice before taking it out this week. I wish I would have tried the key fobs on Monday after I put the original BCM back in...but why would I think it would have worked when it hasn't worked for 5 month beforehand.

 

Yeah, that sounds almost exactly like what happened to me. About a month ago I noticed that the key fob started working again intermittently. My theory is that whatever water got into the BCM is slowly evaporating and reducing the path to ground from the antenna. I'll open up the BCM when and if it ever goes above freezing and see what the board looks like. Actually I'm not even there right now, I've gone south for the winter.

I've also been remiss in posting an update. After protracted negotiations with Valley Cadillac, they finally did, to their credit, refund the entire $1863 they charged me to fix a check engine light (which is still on) and the key fob range issue (which is also still there and they screwed up my odometer in the DIC). When I get home the plan is to pull the instrument cluster and send it, along with the original BCM to Spartan Autoworx. They claim they can reset the cluster to zero miles so that when I put it back in the truck, it will copy over the number from the BCM, which should be the correct value of 30,000 and then we'll be good. I'm assuming the BCM does still have the correct number in it because the number in the DIC never changes as I drive around. Apparently, it's waiting for the number in the BCM to catch up which at the rate I drive should be in about 55 years :-)

 

New to forum but will consider some questions soon

 

I'm finally at the point of attempting to get the instrument cluster off so I can send it out for reprogramming. There's a video here: that purports to show how to do it on a Chevy Colorado, on which the Hummer is based (I couldn't find a video specifically for the H3T).

But I can't even get the first base. The guy says "Just pull the trim panel off", grabs it with both hands and off it comes. But mine doesn', even pulling on it as hard as I cant. Is there some trick to this? Is this video even correct for the Hummer? I could use an expert opinion here.

 

OK well never mind. It turns out the instrument cluster bezel in fact does just pull right off and it doesn't require superhuman strength. The trick was not to pull from the top (which is what I had been trying). The bezel is held in by four clips, two on top and two in the lower corners. I pulled on the lower left corner and that clip released pretty easily. With that out, the upper left clip followed, then the upper right and finally the lower right just popped right off. Didn't even break anything. No tools required. Yay!

 

The nightmare is over!



I sent my instrument cluster and my original BCM and my replacement BCM to Spartan Autoworx for them to clone and reset the IC. And it all worked perfectly. These guys are fantastic. I got one day turn-around, Eric called me to let me know everything had gone well and then he sent it back 2-day Fedex. I put the IC back in the truck, reconnected the cloned BCM, said a prayer and turned the key.

The truck started right up and everything seems to be working, even the radio. The odometer read zero. I drove it about 200 feet and then the correct mileage suddenly popped up on the odometer. The whole process couldn't have been smoother. And as a bonus the RKE keyfob is working again now. So I can highly recommend Spartan Autoworx to anyone needing a new BCM for their Hummer.