HELP newbie BCM issues

[wicked_z71]

First timer here, I've had my HCI lq4 swapped 05 z71 Silverado tuned via efi live for the past few years.
Finally bought hp tuners to do things myself, today I swapped injectors and moved some shift points around
Problem: tune went well, shut the truck down and the blower motor stayed on. I chocked it up to a bad blower motor resistor, so I pulled the fuse and carried on.
Just drove the truck home (it's dark out now so the headlights came on) and my whole gauge cluster/dash lighting is stuck on.
I know this truck inside and out, I took it off the dealer lot and I've had everything apart, I've had the cab off, bed, whole drivetrain out, there's no corner of this truck I'm not confident in. It's been my daily since 2005....so I'm confident this isn't a double coincidence. I tuned it via HPtuners and now the BCM is throwing an absolute fit and doing whatever it wants.
Anyone have any insight here? Any help would be appreciated, as I have to drive this thing to work in the morning.
Thanks in advance and thanks for the awesome Information in this forum that helped me get comfortable using this software!

[5FDP]

It won't be anything tune related as the BCM is not part of the tuning process with the PCM.

I've seen ignition switches do some crazy things but that's just a guess.

[wicked_z71]

It won't be anything tune related as the BCM is not part of the tuning process with the PCM.

I've seen ignition switches do some crazy things but that's just a guess.

Right on, thanks for the reply. I know I didn't flash the body control module, so this doesn't make sense. But, I've read threads where people have tuned and wound up with a stuck "service 4wd" message or other funky stuff going on on the dash.

This truck has some miles on her, right around 240k....so it'd make sense that electronics will start to fail....however, I can't get on board with the idea that I tuned it, turned the key off, and everything sh*t the bed all at once. It's certainly possible, just highly unlikely. just wondering if it's happened to anyone else and what their solution was?

[wicked_z71]

When you tune, all sorts of stuff goes on with the cluster. It flashes different messages, stepper motors make noise....that's what's going on here, it's as if I'm in the middle or "writing" but I'm not. The cluster is stuck on, and my guess is that's back feeding the climate control module.

[Dr. Nopps]

I'm pretty sure it can be brought back to normal without even much difficulty. I forget exactly what others have done. I think they disconnected their battery overnight trying a global reset as well or some relatively basic troubleshooting stuff like that. Just remember in the future to pull out your radio fuse prior to writing tunes to or reading that ECM.

[Steve S]

Why do you pull the radio fuse?

I'm pretty sure it can be brought back to normal without even much difficulty. I forget exactly what others have done. I think they disconnected their battery overnight trying a global reset as well or some relatively basic troubleshooting stuff like that. Just remember in the future to pull out your radio fuse prior to writing tunes to or reading that ECM.

[5FDP]

To prevent any issues with talking to the computer.

Anytime you install something like an aftermarket radio it can still be pulling power from the vehicle even when it's off. Someones even on stock vehicles pulling the radio fuse is a good idea.

I pull the radio fuse on my friends 2011 silverado with an aftermarket deck to stop it from having problems.

[wicked_z71]

Thanks for the help guys. I do have an aftermarket double din. I got to the bottom of the problem, blower motor resistor failed, melted half the connector, and it was back feeding a bunch of stuff in the cab. Doesn't make sense because I had the maxifuse out for the blower motor, but I guess that 5 pin connector on the resistor still has some control voltage on it separate from the power for the fan.
My theory is when I was dialing in my idle it might have dropped a below 12 volts when surging and I had the heat on full tilt (it's cold here in New England) so it pulled a little more amperage through the resistor and ate it up. Can't say for sure, but that's my theory. Obviously I have everything off when writing the tune.
But, Good tip on the radio fuse, I have it fired off a a relay since the original onstar/Bose setup didn't have a trigger wire. So that's always on, which also fires my amp under the back seat. no sense having any extra current draw when communicating with the ecm.

[* _ *]

A sketchy battery can cause the issues you are experiencing. Load test the battery after cycle charging the battery using a 4-6 hours duration on the charger.