VTD/IGN-PCM/BCM/DIM help

[spooledup91DSM]

So, my 05 Denali has some electrical hacks I WILL figure out lol. This vehicle has a reconstructed title from being flooded in NY in 2012. After that, it makes its way to IN where I believe it may have been stolen. I just wanted to give just a little background here.
Upon buying it, the stereo was out of of base model truck and lockex. My truck came with the LUX system. Few things work in it and it has what I'm thinking are some serious ground issues. When seats are moved or windows, etc, the lights and whatnot take a serious and obvious hit as they dim down really bad.
I think most issues will be fixed by finding connectors that still need replacing as well as grounds. Btw, the TECH II indicates that all modules are communicating except the airbag module FWIW.
My biggest concern is finding out what they've done with the VTDS. Here's the rundown:
Within the main harness, closest to the engine, there is a pink wire (my research says pink is ignition related) that has been cut in two where the lower half of the wire has been connected to a black wire which then runs back through the firewall where it splices into a yellow wire (the yellow wire is not cut). Minds you, there are no resistors nor relays in this hack. Just a black wire running from A to B. What the hell is going on? I have a hunch that a lot of things that don't work are related to this if one follows the circuitry and understands how these systems are tied together by the BCM.
Oh, another weird going on. The Retained Power feature, continues to stay on after a door has been opened. Windows goes up and down, the Nav unit actually plays even though there's no sound (it goes back to theft lock once ignition comes on). I imagine the power remains on until the Active Voltage system kills all power. I will attach a pic of the strangeness of the keys here shortly. You will understand why I'm posting them once you've seen them.

---------- Post added at 04:25 PM ---------- Previous post was at 04:06 PM ----------






The H2 key will only start the truck. The GM key must be an original because it works locks and starts the truck. Second pic is of the splice to the yellow wire on top of the column just below the dash where the dash is. Third pic is just to show the ignition has to have been changed because it shows no sign of water damage.

---------- Post added at 04:32 PM ---------- Previous post was at 04:25 PM ----------



Oh, here's where the black wire is connected under the hood.

 

[fiatdale]

A bunch of ignition wires are tapped. Could it have had an alarm or remote start at one point, possibly?

Sounds like a lot of issues could be solved by first checking grounds and make sure they're clean and contacting good. Airbag module doesn't surprise me as its under the drivers seat, and would be the first module to get soaked in a flood. 2012... is this a "Superstorm Sandy" vehicle? I find it odd that the H2 key doesn't work the locks, if the other key works both. Could be that its a new key and the tumblers and old key are worn?

Could very well have been stolen too. Look a the bolt heads for everything near the ignition housing. Do they look like they've been removed? Hard to tell in that pic.

Retained power - check the door latch. Does it still turn off after 15 minutes of ignition being off?

Problems like this can be a nightmare to track down. Just keep track of everything you check so you can rule out things.

 

[spooledup91DSM]

A bunch of ignition wires are tapped. Could it have had an alarm or remote start at one point, possibly?

Sounds like a lot of issues could be solved by first checking grounds and make sure they're clean and contacting good. Airbag module doesn't surprise me as its under the drivers seat, and would be the first module to get soaked in a flood. 2012... is this a "Superstorm Sandy" vehicle? I find it odd that the H2 key doesn't work the locks, if the other key works both. Could be that its a new key and the tumblers and old key are worn?

Could very well have been stolen too. Look a the bolt heads for everything near the ignition housing. Do they look like they've been removed? Hard to tell in that pic.

Retained power - check the door latch. Does it still turn off after 15 minutes of ignition being off?

Problems like this can be a nightmare to track down. Just keep track of everything you check so you can rule out things.

Yes sir. It's a "Sandy" vehicle. According to the dates, it would have to be.
Yes sir, electrical can be an absolute nightmare. I like to think I'm pretty good at automotive electrical though. I have no doubt I'll figure it out but the sooner the better, ya know.
Yea, I forgot to mention the other taps. Probably because they're no longer in use. There aren't any wires other than that yellow that are actively tapped into. I agree that an alarm system was surely there. Likely at the time of the flood. I have checked and added some grounds to no avail. I have a friend at a local GM/ Cadillac dealership who will have diagrams waiting for me tomorrow.
Old tumblers, new key; I'm sure you're right. Never crossed my mind. Duh. lol
That's why it's always nice for remote ideas/opinions. I say remote because there's nothing worse than being face to face with the clueless trying to give their opinion lol. Better to read it in writing so you actually give the theory a chance. Just like the tumblers and key. Never crossed my mind even though it's obvious. I just had myself set on theft and replacement keys forgetting if it works in one, it should work in the others. The days of two keys is well over dummy! (myself)
So there's one issue resolved. Thank you, sir.


*edit* shoot, two things down. Gotta check the doors and actually test the 15min feature of the Retained Power issue.

 

[spooledup91DSM]

Ok, so I disconnected the black wire and jumped the 2 ends of the pink together. She started up with no issues. Even went for a drive and shut it off a few times. No VTD issues. So there's another concern down.
I'm now hoping that replacing the battery cables and fresh grounds will remedy the low voltage issue.
Other problems will likely lay with connectors that still need replaced from its days spent attempting to be submersible vehicle. I just have to get to all of them. Under the console for example; it was never removed during reconstruction. I can't even move the bolts. I'm going to have to drill them out unfortunately.
Ohhh happyyy day.

*edit* thank you again, fiatdale. The Retained Power staying on is definitely caused by the driverside door. It shuts off with the others.

 

[fiatdale]

As far as the airbag module goes, you won't be able to put a used one in. You'd has to put a new one and have it programmed via tech2.

Glad I could help. I've dealt with too many flood jobs before. They can suck!

 

[JKmotorsports]

A lot of electrical gremlins can be traced down to bad grounds. Especially being that the truck was involved in a flood incident, there may be corrosion at one or more ground points, which could be the cause for the huge voltage drop like you described. I'd say that roughly 95% of voltage drop issues I diagnose are due to bad grounds, with the remaining percentage from corrosion or bad connectors/splices that cause high resistance in the circuit. And when you're dealing with low current/low voltage multiplex/databus circuits, any added resistance isnt good and will definitely start causing issues with various electronic modules. Good luck with everything.

 

[spooledup91DSM]

A lot of electrical gremlins can be traced down to bad grounds. Especially being that the truck was involved in a flood incident, there may be corrosion at one or more ground points, which could be the cause for the huge voltage drop like you described. I'd say that roughly 95% of voltage drop issues I diagnose are due to bad grounds, with the remaining percentage from corrosion or bad connectors/splices that cause high resistance in the circuit. And when you're dealing with low current/low voltage multiplex/databus circuits, any added resistance isnt good and will definitely start causing issues with various electronic modules. Good luck with everything.

Well, resistance from splices did cross my mind but I let it do just that while I concerned myself with the more obvious issues.
Ok, here's an example I will use for reference:
The BCM harness connectors between it and the MBEC1 have been replaced (actually I can't remember if the connector AT the BCM has been replaced) by just being cut from the harness. I haven't pulled the tape off from the splice points but what kind of resistance issues would this cause? Will proper soldering of the spliced wire eliminate high resistance if needed? Like I said, I don't know how the splicing was finished before being taped up.
I'm really good with automotive electrical. I understand how the various circuits work and how some are integrally a part of others for the most part, but this is the first vehicle I've torn into with what could be considered a complex system. After browsing some GM electrical guides ive downloaded for 07 (for tge life of me i cant find a guide online for NBS trucks) and up GM trucks and SUV's, I'm quickly learning the circuitry isn't as complex as its made out to be. It's actually really cool stuff, how the modules work, what they control, and how they communicate to perform actions and commands. I mean, I'm really enjoying this stuff! lol
For me, I become almost useless when you start talking about resistance values and whatnot. Sure, i can hook up some subs and amps but I just don't have the education for some things (stay in school kids).