I ran into this issue with my 2017 Chevy Bolt this week. I have been getting amazing mileage this summer, close to 300 per charge, and only driving a few times per week for grocery trips. So it has not been L2 charging for about a month and not driven except on 10 minute trips.
I used it on Thursday and everything seemed normal. On Saturday I tried to use it and when I started it, every check engine warning possible was displayed. It said the state was not correct to shift to drive and that the battery could not charge. The instrument cluster worked, but the main console did not boot up, but the radio was on. I could lock and unlock it, but the windows did not work. It seemed to me that the headlights and cabin lights were dim. I plugged in the L2 charger and went to bed, but the charging indicator stayed orange in the car.
On Sunday I went to the garage and got into the car (which luckily I had left unlocked). I tried to turn it on and it was totally dead. I read these forums and got my trickle charger hooked up. As soon as I turn that charger on, the car started to come to life, as if I had opened a door. But it drew too much current and the trickle charger surge protect disconnected the power and the car died again.
On Monday I called the local Chevy dealer and asked for an appointment a tow. They could not look at the car until Wednesday and told me to arrange my own towing with OnStar or the myChevrolet app. Not exactly stellar customer service. They also told me that if it was towed while not in neutral it could be damaged and that would not be covered under warranty even if the Chevy roadside assistance towed it! I explained that the car was dead and that I could not put it in neutral and they restated the policy to me!
I pulled my son's ICE car next to mine and used jumper cables. Again the car came to life. Everything turned on, but the windows still did not work and the check engine, battery, transmission, stability control and drive warning lights all stay on. It would not shift out of park. After 10 minutes, it did shift out of park one time, them reverted to the previous "not in a correct state" errors.
I plugged in the L2 charger, charging did not start. At this point I disconnected my son's car and the Bolt shut down again. This time I forgot to unlock the doors and so was locked out of the car.
Last night, I decided to reconnect the jumper cables. I did not turn on my son's car, just left both batteries in parallel. I plugged in the L2 charger. Car was still inoperable for about 3 hours, but when I opened the door and the headlights came on, the seemed brighter. After 3 hours I started getting "charging interrupted" alerts from the myChevy app and around midnight the car alarm went off! Very nice for the neighbors. When I went to deal with that, I disconnected and reconnected the L2 charger 5 times. On the 5th attempt, the charging light went green. I hoped that the 12V battery charger would kick in and recharge my battery and my son's battery.
At about 4.00 am I woke up and check the 60Kwh battery level, it was charging. I went down and disconnected the jumper cables and the Bolt did not complain. This morning I verified that my son's car could still start after the long battery drain and the Bolt powered up as if nothing had happened.
As an engineer, this is a terrible design. The 12V battery discharging should have been alerted to me either on the instrument cluster or via the myChevy app before it discharged itself completely. If the 12V battery level is too low, that should be the only alarm on the instrument cluster, not all of the bogus ones such as "transmission failure" - the manual should describe what to expect if the 12V battery fails, it should explain that it may take hours to "jump start" the car, unlike an ICE vehicle. And Chevy dealers and Onstar should be able to recognize this issue and offer solutions, not tell you that if they tow the car and damage it, they are not responsible.
Now I have to waste more time bring the car to the dealer to find out why it totally drained the 12V battery and left me with a completely disabled car.
Terrible design and terrible customer service, Chevrolet.