Pinout of the central control unit on the Volkswagen Polo Sedan.

Once I got tired of disassembling the connector every time I connected something to the BCM and only after that I found out that I didn’t have the right pin or wire. Therefore, I decided to systematize the information about the correspondence of wires and pins to the contacts in the connector.

On the Volkswagen Polo, only two connectors are connected to the BCM - t73a and t73b. Older machines also have a t73c connector. These connectors differ in body color:
t73a - black - 1K0 937 702 D
t73b - white - 1K0 937 702 E
t73c - brown - 1K0 937 702 F

When connected to the block, it is impossible to confuse them, because The protrusions on the connectors are located differently, but inside they are the same.

The connector consists of two internal connectors and a cover. To remove the cover, you need to pry the latches with a screwdriver. The internal connectors are inserted into each other, they can also be separated by sliding in different directions.

The location of the internal connectors inside the cover.

The contacts themselves in the connector are divided into 4 types:
#1 - 0.63 mm wide - contacts 17 to 37 and 42 to 62 - yellow in Figure
#2 - 1.5 mm wide - contacts 3 to 10 and 39 to 41 - Red in Figure
#3 - 2.8mm wide - Pins 1, 2, 11 to 16, 38, 64 to 66, and 69 to 71 - Blue in Figure
#4 - 4.8mm wide - Pins 63, 67, 68, 72 and 73 - green in the picture

And now about what wires and pins fit there.

Wires:
#1 - 000 979 009E (0.5 mm²)
000 979 164E (0.75 mm²)

#2 - 000 979 025E (0.5 mm²)
000 979 150E (1.0 mm²)
000 979 255E (1.5 mm²)

#3 - 000 979 026E (0.5 mm²)
000 979 151E (1.0 mm²)
000 979 242E (2.5 mm²)

#4 - 000 979 027E (0.5 mm²)
000 979 152E (1.0 mm²)
000 979 243E (2.5 mm²)
000 979 308E (4.0 mm²)

Pins:
#1 - N 907 647 01 (wire 0.5 mm²)
A 008 545 (wire 0.75 mm²)

#2 - A 018 545 87 26 (wire 0.2-0.35 mm²)
A 018 545 86 26 (wire 0.5-1.0 mm²)
A 018 545 85 26 (wire 1.5-2 .5 mm²)

#3 - A 015 545 04 26 (wire 0.2-0.35 mm²)
A 013 545 76 26 (wire 0.5-1.0 mm²)
A 013 545 78 26 (wire 1.5-2 .5 mm²)

#4 - A 018 545 47 26 (wire 0.5-1.0 mm²)
A 018 545 49 26 (wire 1.5-2.5 mm²)
A 018 545 51 26 (wire 2.5-4 .0 mm²)