The battery pack arrived to the garage yesterday and I removed the lid. I also bought an ELM 327 OBDII to Bluetooth.
I made a simple cable to connect the ELM 327.
I bought the female OBDII from a junkyard, the guy gave me one which has the ability to reconfigure the pins. I removed all pins and added only four - pin5 (GND), pin16 (12V) and pins 6+14 (CAN). It turned out that the round connector in the Leaf battery has a standard 0.1" spacing, which was neat because I could use simple standard female headers for that end. In the upper left of the round battery connector are two 12V pins. Upper right are two CAN pins. Just below the CAN pins are three GND pins.
The ELM 327 and BMS powered up on first attempt,
and I could connect with the App.
Everything just worked. Thanks for the info in this thread. Thank you for the App, Turbo3.
Looks like my pack is in good condition. It's from a 2013 Leaf with only 6800km.
Next step will be to take the pack apart and connect it 3p. Then I will attempt the modifications to the BMS.