GM’s Final Software Update for The Chevy Bolt – What does it do?

The new software is supposed to monitor the cells for voltage variations much more closely to prevent a Bolt Fire. The idea is to proactively look for the conditions that could lead to a fire, avoid them, and get the battery replaced before it happens.

It also monitors the battery after the charge completes to ensure nothing bad happens. As per GM’s Service Information Tool, which has some information on the new software and DTC codes, this is added:

Thermal Monitoring

[…] If conditions are right, thermal monitoring may remain active after vehicle OFF or at the completion of plug-in charging for 10 minutes up to 12 hours. With vehicle OFF thermal monitoring, the high voltage contactors will be closed and the K1 14V power module will support the 12-volt battery. […]

The following will occur only if thermal runaway is detected – regardless of Vehicle ON/OFF state:

– The vehicle parking lights will flash and the horn will sound continuously until the 12-volt battery is depleted

GM’s Service Information Documentation for the new P0BBD DTC Code

Many Bolt owners report that their charging station shows power still flowing to the car after the charge has completed for 4 hours. This matches what’s mentioned above about the 14V power module and contactors closed. It means that the car will use the wall power to run the 14V system and monitor the battery for up to 12 hours after charging has completed. According to the above, it will also run when unplugged.

4 thoughts on “GM’s Final Software Update for The Chevy Bolt – What does it do?

  • The “final fix” doesn’t actually fix anything, though. It’s a fancy fire alarm. If the horn blows and the lights flash, it’s gonna blow, get away, and hope it’s not in a garage that’s in a house, because if it is the house is going down with it. In my case, it lives in the driveway anyway (no room in the garage), but this reinforces that practice.

    The only real fix is for GM to force LG into at least the same deal they made with Hyundai, and replace ALL of the pre-2020 batteries with new ones using the 2020+ chemistry and construction practices; the whole thing, not just “bad” modules if any exist at the moment of testing. Until that’s done, a Bolt should never be parked, especially if charging, inside a building.

  • After seeing the latest Bolt Recall of July 23, 2021 I complied with GM’s recommendations for charging.

    However, I’ve since kept my 2019 Bolt parked outside after charging in-garage. I did manage to reconfigure my L2 charge Cable to facilitate outdoor charging.

    Now I keep my Bolt outdoors for charging and post-charge.

    Hoping GM & LG fix these batteries before winter arrives!

    Ray Iannuzzelli

  • What is the version no. of this updated software.
    Mine is version: 46.1.6

  • Anyone know if this is generally available for all of us now waiting for replacement batteries for 2017-2022 Bolts (and any id/version/part number if so)? It sounds like it could be useful as an interim safety patch, but my dealer service people seemed to have no idea what I was talking about when I referenced this. I got referred to a generic Bolt info number, 833-EV-CHEVY, where some nice lady who may or may not have been a robot read me the recall notice, verbatim, each time I asked about this software update.


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