The Chevrolet Bolt EV and Bolt EUV are facing a difficult moment as defective battery modules could cause them to catch fire. A massive recall for around 141,000 examples globally is currently underway. Owners have received specific instructions on how to handle their vehicles, such as parking them outside, until the necessary fixes have been completed. But Chevy still has lingering concerns about the quality of the replacement modules. Put simply, it is not confident battery supplier LG Chem can make defective-free batteries.

The Detroit Free Press reports that despite having "hundreds of people" working seven days a week on finding the cause of the defect, the American automaker remains unconvinced the new modules will be fully safe.

In fact, GM has decided to shut down the Bolt assembly line at its Orion Assembly plant until it's convinced those new modules are 100 percent safe. "If we took the battery stock that's in the field right now or at a warehouse, we're not confident that it is defect-free," a GM spokesperson said.

"Because we are not confident that LG has the capability to build defect-free products, we've put the repairs on hold and we are not building new Bolts. We're not going to start recall repairs or start building new Bolts until we're confident LG will build defect-free products."

LG makes the batteries at its facility in Holland, Michigan, which is good because GM is in close proximity to study the company's production methods with a team of engineers at the factory carefully observing things. For its part, LG is supplying GM with necessary data. The same GM spokesperson reiterated LG wants to resolve the issue just as badly as the carmaker.

Both companies know what caused the fires - a torn anode tab and a folded separator within the modules - but neither understand what's causing the defect to happen during the manufacturing process. Equally troubling, they don't know whether all Bolts are affected or not, hence the costly decision to recall all of them.