Service Hybrid System 08 Tahoe
 

I have some play in my steering gear, which the stealership said was the steering gear assembly. I disconnected the hybrid battery and the the 12v battery properly and serviced my steering gear. Now that I have it all back together, the truck will not start.
All the lights and systems work as normal and no indication that the 12v battery is low. But when I try to start the vehicle The headlights blink off when turning the key to start and shortly after I receive "Service Hybrid System" in the dash.
There is also a buzz that seems new somewhere in the engine compartment, but have not located it.
I have read what is available online about this and it all seems to point to the transmission wiring harness, 300v battery bad or 12v battery low. I am waiting on the wife to get home to try to put jumper cables on it to see if it starts.
Other than that its off to the stealership it goes.
My question is: Other than what is stated above, has anyone ran into this issue and if so were you able to resolve it without stealership involvement?
The vehicle only has 26k miles on it so the hybrid system is still under warranty.

I was able to get my Tahoe running again.
Tools needed: 2 beers and one friend.
Give your buddy a beer and take one for yourself. Explain everything you did to this point and drink your beer. Then pull the hybrid service disconnect and blow in it like its a 1985 Nintendo Cartridge and reinstall. Sit back and enjoy the engine start when you turn the key.

Third time really is the charm. Weird it must have been a little loose, but double checked it. Really glad it working now and will go straight there if this happens again.

Beer is a wonderful thing :p
Thanks for the follow up...often times the fix is usually the simplest thing...

Where is the hybrid service disconnect located?? Having the exact same issue!!

so this is ridiculous 27+years automotive and diesel mechanic. I had the same issue after just servicing the 12volt battery. I took out the disconnect for the hybrid and the vehicle wouldn’t start, and had the service hybrid system warning. I pulled the plug again and as you put it, blew in it like it was a 1985 Nintendo cartridge……..NO D4mn way! It worked! I was dumbfounded! And excited all at the same time! My childhood video game experience was useful!😂