1) The second dealer will always need to run their own diagnostics for one simple reason: Accountability. When dealer B submits for the warranty replacement (under the recall) of the battery pack, GM will ask them to provide documentation that the pack was outside of GM parameters. They cannot simply say "Dealer A said so". GM won't accept that.I took my 2017 Chevy Bolt to my nearest dealership last week to apply the final fix for Recall #N202311731-01 (Safety Recall - High Voltage Battery May Melt or Burn). After nearly 6 hours of waiting, they reported that they had inspected the battery pack for the recall and concluded that a "battery pack replacement" was needed. However, they indicated that they do not currently have any Bolt techs on their staff. Therefore, they were unable to order the replacement parts or perform the repair. They referred me to another dealership.
I took the vehicle to the second dealership this morning. They indicated they could not use the diagnostic results from the first dealership and would have to start over and run the diagnostics themselves. (That makes sense to me.). However, after running the diagnostics, they reported that the vehicle passed and only needed to be reprogrammed. No hardware replacement was needed afterall!
Have there been other reports of inconsistent recall diagnostics? It is deeply disturbing that the vehicle can fail one day and then pass 4 days later. How confident should we be in the diagnostics?
2) If Dealer A does not have an EV certified tech, I wouldn't trust their diagnosis as much as I would trust Dealer B's diagnosis. Rather than the vehicle failing one day and passing four days later, I suspect Dealer A simply misread the data. Having a service department that knows EVs is a big deal.