LB7: massive problems loading a tune on my 03 SLT Duramax

[fastpunker]

I had my friend try to put his programmer on my truck last night that we know for a fact is not on any of his trucks currently and know that it works and it still would not load a tune. When I took the truck to the local chevy dealership they hooked up the tech-II to it and it pulled a vin number from the ecm that was along the lines of 89##A#5###90 (not exactly what it said, but you get the idea). I took the junkyard ecm I picked up and put that into another truck and then programmed it to my VIN #, pulled it out and then stuck it into my truck and it immediately flashed it to the corrupt VIN once I turned the key. So I am thinking another control module is messed up and corrupting all the control modules in the truck since they all work on a common network and not in a series... Kinda leaning to the BCM but not sure and dont want to spend $300+ on it for that not to be it. Im going to try and clear out the security light today and see if thats messing with anything.

Anybody have some thoughts on if it could be the BCM or if its some other module?

 

[Josh2002cc]

I had the same problem, took it to my local dealer and they found a mystery wire broken someplace that was keeping the security light on saying there was a lost communication with the BCM. They jumped a hot wire to the BCM and problem solved.

 

[JustinD]

Hope you figure it out, 03-04 trucks seem to be a PITA to flash either way?

 

[Mike_S]

The vin is stored in all 3 modules. IIRC it displays from the BCM (ECM is insignificant in this case. Use a bench harness and i bet it will show the same vin you programmed it to.) when scanning with the ALDL connection. If the BCM has corrupt data then the security system would be all freaked out. See if the tech2 can reprogram the vin into the BCM and if that helps make any progress. One more thing, check all your grounds and battery connections, battery condition, ect. Poor power can cause weird issues.

 

[fastpunker]

Hope you figure it out, 03-04 trucks seem to be a PITA to flash either way?

Do you happen to know what wire it was that was cut/damaged?

 

[fastpunker]

The vin is stored in all 3 modules. IIRC it displays from the BCM (ECM is insignificant in this case. Use a bench harness and i bet it will show the same vin you programmed it to.) when scanning with the ALDL connection. If the BCM has corrupt data then the security system would be all freaked out. See if the tech2 can reprogram the vin into the BCM and if that helps make any progress. One more thing, check all your grounds and battery connections, battery condition, ect. Poor power can cause weird issues.

Thanks for the good input! I'll have to check the grounds and such....
Also I'm a bit new to the gm lingo for terms.... what is IIRC and ALDL?

 

[Mike_S]

IIRC:If I Recall Correctly

ALDL:Assembly Line Data Link, also known as the diagnostics port.

 

[fastpunker]

An update. I tried the battery reset method, left both batteries unplugged for 3 hours and grounded the positive cables. Doing this did nothing but reset the clock on the radio.... security light still on. Checked grounds and power of the batteries and all is good there. Im out of ideas.....

 

[Josh2002cc]

An update. I tried the battery reset method, left both batteries unplugged for 3 hours and grounded the positive cables. Doing this did nothing but reset the clock on the radio.... security light still on. Checked grounds and power of the batteries and all is good there. Im out of ideas.....

Check the power wires going to the BCM. That was where my problem was....

 

[fastpunker]

Check the power wires going to the BCM. That was where my problem was....

Do you know which wires they are... color/stripe?

 

[Josh2002cc]

Do you know which wires they are... color/stripe?

I am sorry but I do not. I gave up and took it to the dealer. Wasn't happy but it got fixed.

 

[fastpunker]

Does anybody know off hand what wires are the power wires to the BCM? Or does anyone have a wire diagram for the BCM on an 03 SLT or LT with the heated leather seats and such?

 

[Dirtymax03]

Subscribing

 

[fastpunker]

Subscribing

what does that mean? (sorry, still new to this forum)

Also, does EFI Live need an accurate vin # to load a tune or could I get around my problem going that route?

 

[Sledhead]

what does that mean? (sorry, still new to this forum)

He is going to follow you thread. By posting he automatically becomes "subscribed". This can also be accomplished in "Thread Tools" without posting.

Also, does EFI Live need an accurate vin # to load a tune or could I get around my problem going that route?

Vin# Yes, around problem No

 

[fastpunker]

Ok. Thanks.

 

[Dirtymax03]

He is going to follow you thread. By posting he automatically becomes "subscribed". This can also be accomplished in "Thread Tools" without posting.



Vin# Yes, around problem No

Thanks i didnt know that about thread tools

I have a prob with hp tunner worked first time then second time it said vin not licensed?

 

[fastpunker]

To end the discussion, after trying different ecm's reflashing the TCM and also trying a new BCM (at separate times) nothing worked.... conclusion was all modules needed to be replaced at the same time and flashed with latest updates. I didn't feel like spending the money to do it, so I ended up selling the ec/sb (had 275K on it anyways) and picked up a ccsb, tuned it right away and couldn't be happier!