So my uncles yukon went stupid in the middle of the drive and i'm trying to figure that state of his battery. I'll throw up the info from Tech2 then paste a longer post from else where with more background. If anyone has insight to the battery or larger problem I'd love the help at this point.

Hybrid battery 1-20
13.5
12.9
12.5
12.1
11.6
11.4
11.3
11.3
11.2
11.2
11.2
11.2
11.2
11.6
11.6
11.8
11.8
12.0
12.2
13.0

Precharge overtemp, too short, too long - no no no
battery pack cel 233v
battery terminal 12.8
calc. bat current -0.1
batt. current se 2.51v
batt mod 1 tem 25c, 3.2v
batt mod 2 tem 24c, missing
batt mod 3 tem missing, 3.2v
batt mod 4 tem 27c, 3.1v
batt inlet air 25c, 3.18v
Batt outlet air 26c, 3.14v
control module voltage 11.79v
hvic Source nad return current .2mA, .1mA
hybrid battery SoC 44-58%
Contactor Sys req ckt 70%
Contactor Sys req sig open

Contactor Sys req status open

Current Sec high range 0.0
Current Sec medium range -0.1

Current Sec low range -0.05

Batt pack resistance 0.024 Ohms

Our story so far....

To expand a little on the day everything went to hell. I was called because the car had went from running fine to saying Engine Power Reduced and began running like crap. Then it stalled out 5 minutes later. He restarted it drove normal for a bit then the same things happened again. Which is when he called me. I got there and checked the codes and there was one for a cam shaft sensor short and google told me that could cause the engine power reduced error. So I changed that in a nearby parking lot. Cleared the codes, started it took off. The same thing happened yet again. Checked the codes again and the cam shaft sensor plus something else was bad. I cleared the codes again thinking maybe i had forgot to clear the codes. It drove for nearly and hour till we were about 20 minutes from home. It was running normally then, Engine power reduced, lot of codes for multiple things including some for sensors, transmission, timing (i think), and one with no description that i looked up to be "dealer specific code" which I believe i tracked down to something relating to the hybid ECU. This was several months ago so I am trying to recall. I probably have pictures of all the error codes somewhere.

The car would no longer run. It started, ran rough for maybe 5 seconds the shut off again. We towed it to a local tech shop that I usually use for electrical issues. They spent about 30 minutes and said it was most likely the hybrid computer or a short somewhere. The engine bay is clean and virtually oil free and the wiring in general looks great. But they were not certified to work on hybrids so we took it to the local dealership. They charged him for 5 hours of diagnostics to say the same thing and quoted 6k for a new module plus install? I think. I felt like we were getting screwed but had no way to check anything they were saying. They agreed to install a used one and program it but with no warranty because it wasn't there part. Having no other realistic option that is was he did. Then the dealership said the new module wouldn't take programing but was vague about the exact errors and then said it was shorted internally and there was nothing they could do. Returned the module and did more research which is about the time I originally landed here.

Once I found I could use Tech2, gds2 and SPS2 to do everything myself we decided to bring the car home from the dealership. Which is when we discovered the parts missing and all that nonsense. In order to lear the programs and procedures a little better I decided to put the car back together and try to reprogram it myself to see where it failed and how the software worked. Well, everything programmed without error. It did the full sequential reprogram of the hybrid module no problem.

I don't know what to do. Everyone did agree it was the module but it seams to be acting fine. The dealership said it was shot and they couldnt get a response from anything it was connected to but that simply isnt true apparently. Only the low voltage errors might be keeping it from starting. As far as I can tell none of the other errors should, they are mostly for sensors and support systems. Right now I am just trying to figure out why it wont start without just throwing money at it. More and more I am thinking about the battery but I just don't know enough about them yet

 

I am no expert and I am hoping some of the ones on this forum will jump in.

I would suggest that you remove the battery for the vehicle, open it up and have a look at the cell bus bars. My gut tells me you have a lot of corrosion.
Also, considering the wide voltage range across the battery cell packs you likely have a few bad cells as well.

Working on the battery seems like a huge risk at first, but once its open and you sit and study the device, you will quickly get a thorough understanding of the logic involved. You will discover its a rather repetitive and boring job lol.

I painstakingly reconditioned my 2013 Silverado battery cells 4 months ago. Each one had at least 4, each progressively deeper, discharges, re-charges and capacity tests. I got everything working fine, most of the cells are withing 0.02 volts from each other and my mpg improved. Also I could now step on it in and not have the engine red-line immediately as its trying to overcome the battery pack power deficit.

Since I tow a heavy 2 horse goose neck trailer around all summer I decided to buy new Lithium cells from Jack at https://projectlithium.com/.
The "yukon" lithium packs are out of stock most of the time so I jumped on the chance to grab one. I am hoping get it delivered within the week.

That being said, I will have about 50 NiMH cells in very good shape available shortly and a couple SkyRC Q200 hobby chargers for reconditioning cells.
I also have a spare battery case with controllers, fan etc. I will put them up in the marketplace when I get a chance.

 

Bus bar corrosion is a false boogeyman 99.9% of the time.

The 5 second "runs" are likely just the battery spinning the engine, and the engine failing to start. Repeated efforts to start without actual running will deplete the hybrid battery. A healthy hybrid battery at a normal state of charge should have 50+ start attempts in it before the battery is flattened.

That battery is either destroyed or beyond drained. Nothing 100% conclusive concerning its health can be stated, BUT given the highest voltages are on the ends, and they are progressively lower towards the center is strong evidence of severe deterioration, but with all voltages listed below nominal, there's a small chance it's just due to being drained.

If forced to make a determination on the data provided, I would say it's complete toast.

 

Soo not sure what to make of this. Last night I disconnected the 12v and put it on the charger. In the morning the 12v was charged and the HV battery read 265v. When I connected the 12v the HV dropped to 248. When I turned the key to the ON position the high pitched whine started from the box next to the 12v battery. For the first time I watched the ready out on tech2 while it was whining. The voltage in the HV battery began to drop and the 12v batter began to drop.. 2 or 3 minutes later when it stopped the HV was at 212 and the 12v was 11.1v at 3%. As soon as I disconnect them from each other both battery's start to regen some voltage. I can watch the voltage tick up on the 12v and after a while it back up to 230's on the HV side.

 

Your HV battery is completely empty. 265V is completely depleted.

296V is the lowest functional voltage for a battery with sufficient charge to handle a few start attempts.

Now it sounds like your 12V is weak too.

 

even if the battery has taken a dump it should be able to get the engine running .. i already have put about 6,000 miles since it went "bad".. yeah it was shitty over the winter time but now that it's warmed up the mpg is great again... nothing really to cry about ... plus it buys me some time to save more money


I made a small mistake deleting the P08A0 Code though because it forced a Fail safe mode...


But a P08A0 might mean Bus bar corrosion as the DTC states "High module resistance"

 

You just really have to feel included, don't you?

(1) Wrong
(2) Wrong

Given what has been posted thus far, if you had even a rudimentary knowledge about these batteries, you wouldn't have posted any of that.

 

i got the code 6k miles ago i'm waiting still for it not to "work" i.e not start at all.. this is my daily driver... Yeah i can use my Toyota corolla and get 40-44mpg to work but the suv is more fun to drive... plus too many close calls with the other idiot commuters I rather not clock up the miles on my corolla anyways.... This is a disposable suv. if it gets wreaked into... if i get another SUV it's going to be a Chevy Avalanche E85 Flex Fuel...


26.1mpg is my last fill on a "dead" battery..