willeert wrote:How does GM decide to replace a battery? How do they make up their minds a battery is failing and requires replacement?
The car's onboard software reports issue like this to GM directly - they've been contacting people with problematic batteries to arrange for replacement.
The updated battery software has been known to cause wonky range estimates, it may take a charge cycle or two for things to settle down. Meanwhile, it sounds like your dealer is following up for you - at this point you'll just have to wait and see what they come back with. But if your range continues to be suspect and you don't hear back from them in a timely fashion, then by all means escalate the issue!