as far as the PCM update goes, Bulletin 10-034 came out 7/29/2011 replacing Bulletin 09-058 (PCM udate)
Bulletin 12-048: if the IMA battery needs replaced they'll replace it with the latest updated battery and they'll swap the junction board over to the new battery.
Now the ONLY real issue I can see from just reading the Bulletin is if someone installed the wrong PCM software per your IMA battery code, looks like there's been some issues with that, here's some of the Bulletin:
BACKGROUND
Due to improvements in battery manufacturing
efficiency, once stocks of original IMA batteries are
depleted, new battery designs will be available for IMA
battery replacement. Each battery type requires that its
battery control software be matched to its IMA battery
type. Failure to match the software with the battery will
result in reduced IMA battery life.
In addition, if the battery condition monitor (BCM) or
the motor control module (MCM) is replaced or
reprogrammed, matching IMA battery software must be
installed in that control module to maximize the IMA
battery's life.
This service bulletin includes these subjects:
• Identifying IMA battery types
• Determining correct IMA software and matching it to
the IMA battery
• Installing IMA battery software
• Replacing BCM/MCM hardware and updating its
software
• Checking for an IMA battery/software mismatch DTC