NHTSA Complaint #11434182 — 2020 CHEVROLET BOLT EV

This is a comment on an existing open recall (nhtsa chat said to use this form). Related to the Chevy Bolt recall 21V650. The latest information from GM at https://media.gm.com/media/us/en/gm/home.detail.html/content/Pages/news/us/en/2021/sep/0920-bolt.html contains this: "Within approximately 60 days, GM will begin launching a new advanced diagnostic software package that will increase the available battery charging parameters over existing guidance. The diagnostic software will be designed to detect specific abnormalities that might indicate a damaged battery in Bolt EVs and EUVs by monitoring the battery performance; alerting customers of any anomalies; and prioritizing damaged battery modules for replacement. It is GM’s intent that further diagnostic software will allow customers to return to a 100 percent state of charge once all diagnostic processes are complete." I would ask NHTSA to require GM to publicly describe how they tested and verified that this new software will find 100% of battery packs with faulty cells. For example by building a significant number of battery packs with known faulty cells in different configurations and confirming that all packs with faulty cells were correctly identified. This doesn't require the publication of proprietary information, only a description of the verification procedure and results. A previous software update was supposed to detect faulty packs but it did not work so a more robust test is required this time as they intend to use the information provided by this software to determine which packs to replace. Thank you