2009 chevy silverado "service hybrid system"
 

I have a 2009 chevy hybrid mode 2.
last night the truck ran fine, in the morning it wouldn't start. There is a "Service Hybrid System " indicator light on now. I changed the 12v battery, checked fuses and checked voltage from the hybrid batteries, they total 309v when i checked them. What could be the issue?

Re: service hybrid system
 

The issue is cross posting the same thing in 3 different places.

The next issue will be you responding to the above.

Re: service hybrid system
 

Do you really think that is the problem? 🤷‍♂️

If you can't be helpful just stay quiet.

Re: service hybrid system
 

you need to use an obd2 scanner and an app to figure out what the issue is but most likely your HV battery is going bad if its just an unbalanced situation doing some conditioning could extend its life but if there is a bad cell (aka blade) it is not going to work and will need Speed Test to be repaired or replaced.

Re: 2009 chevy silverado "service hybrid system"
 

pull the codes

a cheap OBD2 might be able to get the code from the freeze frame data