General Motors last night outlined fixes for the potentially flammable Chevy Bolt EV and EUV which include both hardware and software updates, some of which are in place with immediate effect.

New battery production

LG battery plants in Holland and Hazel Park, Michigan, have resumed production. In addition, LG is adding capacity to provide more cells to GM. As a result, replacement battery modules will begin shipping to dealers as soon as mid-October.

The root cause of the “rare circumstances” that could cause a battery fire is two manufacturing defects known as a torn anode and a folded separator, both of which need to be present in the same battery cell, GM said.

LG has implemented new manufacturing processes and has worked with GM to review and enhance its quality assurance programmes to provide confidence in its batteries . LG also will implement these new processes in other factories that will provide cells to GM in the future.

Prioritised battery replacement

GM will continue to prioritise Chevy Bolt EV and EUV customers whose batteries were manufactured during specific build timeframes where GM believes battery defects appear to be clustered. The company has established a notification process that will inform affected customers when their replacement modules will be available.

The new batteries will include an extended battery eight-year/100,000 mile limited warranty (eight-year/160,000km in Canada).

New advanced diagnostic software

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 by monitoring the battery performance, alerting customers of any anomalies and prioritising damaged battery modules for replacement.

Further diagnostic software will allow customers to return to a 100% state of charge once all diagnostic processes are complete.

This new software, which will be provided to all Bolt owners, requires dealer installation. Owners will be able to start to schedule installation at dealers in approximately 60 days.

Updated guidance on parking

“In an abundance of caution” GM is still recommending customers leave ample space around their vehicle wherever they choose to park.

“GM is not aware of any fires that have occurred where customers followed this safety guidance, in parking decks or otherwise,” it said.

The instructions remain to set the vehicle to a 90% state of charge limitation using Target Charge Level mode. Charge the vehicle more frequently and avoid depleting battery below approximately 70 miles (113km) of remaining range, where possible. Continue to park vehicles outside immediately after charging and do not leave vehicles charging indoors overnight.

“We’re grateful for the patience of owners and dealers as we work to advance solutions to this recall,” said Doug Parks, GM’s head of global product development, purchasing and supply chain.

“Resuming battery module production is a first step and we’ll continue to work aggressively with LG to obtain additional battery supply. In addition, we’re optimistic a new advanced diagnostic software will provide more convenience for our customers.”