Did I fry my BCM? 2013 1500 LTZ 5.3 no gauges, no lights no, ignition nothing but CEL

[Mrjack55]

I'll try to make this as short as possible, but it's a lot of information. Sorry in advance.

I have a 2013 Silverado 1500 ext cab LTZ with an LC9 5.3.  The truck has 194000 on it so I decided to build a new motor for it.  I moonlight in a machine shop, so I used a 2007 doner LC9.  I rebuilt it with mostly stock rotating assembly, but added a BTR Truck Norris cam and springs.  The DOD and VVT have been deleted.  After the swap, I had no gauges, no interior or exterior lights, no ignition, nothing but the CEL.  We tried a few different tricks, but swapping keys seemed to work.  Could have been something else, but I'm not sure. 

The other night I was working on the tune getting the ECM set to the new cam.  The engine was running (poorly) but everything seemed fine.  I made a few changes to the tune, shut the engine off, and removed my HPT from the OBD.  Everything went dark again.  Nothing other than the CEL and the 4WD selector knob showed power.  No locks, no windows no lights, no horn, no power to the OBD, nothing.  Has anyone else experienced this?  The "pros" on the tuner forum say it's not the ECM but maybe the BCM.  I looked for blown fuses, but couldn't find anything obvious.  This truck is my daily driver, and it's now a big red brick sitting in my driveway.  Any ideas, or has anyone else seen this?  Could it be the antitheft system locking me out?
Thanks

Jack

Edited July 16, 2023 by Mrjack55

[richard wysong]

check the underhood fuse box for corrosion on all ecm/ ignition fuses, could also be a ground issue

Edited July 16, 2023 by richard wysong

[Mrjack55]

3 hours ago, richard wysong said:

check the underhood fuse box for corrosion on all ecm/ ignition fuses, could also be a ground issue

Yeah, been through that.  I hate electrical gremlins.  

[dna9656]

Electrical gremlins are the worst kind of gremlins. I am really sorry, but whenever you depart from stock, OEM configurations, you can expect ****** to not run right. My advice; stick to what GM did. It's amazing how all the ****** runs right.

[swathdiver]

Get a bi-directional scan tool on it that can read the BCM codes.  It probably is the BCM and a new one or used one will have to be programmed to your truck.

 

Did you keep the flat top pistons from the donor motor?  

[Mrjack55]

6 minutes ago, swathdiver said:

Get a bi-directional scan tool on it that can read the BCM codes.  It probably is the BCM and a new one or used one will have to be programmed to your truck.

 

Did you keep the flat top pistons from the donor motor?  

I did not keep them, but replaced them with new stock replacement flat top pistons.

[Mrjack55]

On 7/17/2023 at 1:51 AM, dna9656 said:

Electrical gremlins are the worst kind of gremlins. I am really sorry, but whenever you depart from stock, OEM configurations, you can expect ****** to not run right. My advice; stick to what GM did. It's amazing how all the ****** runs right.

Yeah, I know.  But, what fun is that?