[thatonehoonigan]

Hey everyone, having the first ever problem with my 16 2SS M6. I have a parasitic draw that is killing my battery in just a few hours. Only have 2 codes, P069e and P2535.

I have already replaced the battery 3 times and changed the key FOB battery twice as well.

I was able to narrow it down using a clamp meter and pulling all fuses. When I pull Display Fuse F16 in the trunk fuse box the draw goes away. This led to me realizing my Infotainment screen backlight always stays on when car is off. This made me believe it was HMI, BCM, or an update, so all these required a trip to the dealer for me (unless I'm mistaken).

I take it to the dealer; give them the info I have and tell them what I believe is the issue. Dealer was adamant they would like to do their own diagnostic. They come back and tell me HMI and BCM both test fine and that there is no pending update. They kept it for a week testing various things and couldn't find the issue, so they tell me they were getting a corporate GM Engineer to help them figure it out, they have the car another week and come back telling me that there is a fault in the Instrument Cluster that is causing the codes and the parasitic draw by keeping the infotainment on. Now I am far from an electrician, but I feel like this is unlikely to cause the infotainment to never shut off. Anyone have any ideas or perhaps a test I can do to either confirm or deny this finding of the dealership?

So far, I know the draw doesn't go away with just the infotainment screen pulled out, I have to pull the Display Fuse to stop the drain.

Car is tuned by Brett (Pray), Has headers and full exhaust (yes, I did relocate the section of wiring harness in the engine bay that likes to get melted by headers and it is wrapped as well), lowered on springs (yes, I did relocate the wiring harness in the wheel well), MM Catch Can, Rotofab Intake.

as far as electronics I have Diode Dynamics side markers and a third brake light flasher. I also have an extra ground cable from the negative post to the water pump bolt in the engine bay. Everything else is bone stock.

Car has 75k miles and 50k of those have been with these modifications. Like I said this is literally the first problem I've ever had with my car in the 6 years I've owned it.

I apologize if it is long winded just wanted to be thorough, Thanks in advance

[m6-lt1]

Put the stock side markers in or unplug the diode dynamics ones.

[ctrlz]

Originally Posted by m6-lt1

Put the stock side markers in or unplug the diode dynamics ones.

I agree.
You need to eliminate this as possible source of the problem.
Unfortunately these diodes can create alternate paths for current drain in some cases. Even if you use the proper resistors, etc.

Different thread, same codes, also diode dynamics:
https://www.camaro6.com/forums/showthread.php?t=575935

P2535 can happen when fuel pump control module wiring shorts to ground.

I'll append a bit here:
If the car had no draw with the diode dynamics lights and was stable for months/years, then they are probably not implicated.
then I would think it is more likely you have damaged wiring somewhere.

[arpad_m]

Diode Dynamics side markers causing this issue would be a first, or at least very-very unusual. I suspect that it's the third brake light flasher, every one of those I've seen were primitive junk from China. Maybe OP has a better made unit though, we don't know yet.

I second the idea of disconnecting aftermarket electronics one by one until the issue disappears (or if it doesn't, then maybe it's indeed the HMI or the BCM.