Received my programmer ahead of schedule, was able to read data of both CMU12 and CMU8 and proceeded to re-ID CMU8
Replaced the board and started ODBZero: temperature values are now reported correctly, however cell voltages were still off (same 329.78V as with original CMU12?)
DTCs P1A5D & P1A81 both relating to CMU12 low cell voltage which was confirmed 2.1V for IDs 85-88 (all measured a healthy 3.88V though).
Looks like cloning the eeprom isn't enough, some sort of HW mod is also required. Slight differences have already been documented, see link http://myimiev.com/forum/viewtopic.php?t=4302
Connecting the slave board and running 'sense' wires back to the cells did not change any reported voltage. But during the course of swapping boards and messing about I lost CAN communication with CMU12 again (U11AB)?! Looks more and more like a CAN/BMU problem at this stage:
1. car only charging to 3 bars, CMU12: 2 cells reporting high/low voltage, battery temp 57deg
2. after dropping battery pack and troubleshooting actions: CAN communication lost with CMU12 (329.78V 205deg C)
3. new 8 cell CMU with cloned 4 cell EEprom reports correct battery temp (13 deg C) but low cell values (P1A5D & P1A81)
4. after troubleshooting actions: CAN communication lost with CMU12 (U11AB, 329.78V 205deg C)
Planning do main battery CAN termination resistance check next and swap position with CMU6 but if that doesn't reveal anything new then I'd say I'm dealing with a BMU issue??