Traction Battery Voltage Sensors

Hi Prius chat members ,
I have a rescued 2001 NHW11 with the intention of maybe getting it back road worthy . Its been stood for some time so while I was working on the traction battery I thought i would take the opportunity to understand its operation and one thing I couldn't find is how the HV battery ECU reads the module voltages . I thought it just checked each pair from the sensor wires then noticed the first half of the pack they were on the negative and the second half they are on the positive so then wondered if it checked groups of modules , like
2 to 20
4 to 22
and so on , or does it use some other method .
I have numbered my modules 1 to 38 starting from the ECU end.

Sorry if I have posted this wrong as this is my very first forum post ever.