Error in ga-z170x-ud5 motherboard manual for SYS_FAN connector pinout?

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The motherboard manual mb_manual_ga-z170x-ud5_e.pdf shows the SYS_FAN connectors on page 26. The pins for SYS_FAN are listed as:
1 GND
2 Speed Control
3 Sense
4 VCC

I have 3 pin case fans. With GND and VCC on the outer pins, there is no possibility of plugging in 3 pin case fans to contact GND and VCC.

Also every reference I find for 4 pin fan pinouts is different than shown in this manual. See http://www.pavouk.org/hw/fan/en_fan4wire.html
http://www.allpinouts.org/index.php/Motherboard_(CPU)_4_Pin_Fan

Also it seems unusual to have the SYS_FAN connector specify VCC instead of +12V. VCC normally refers to +5V.

Are the 4 pin fan pinouts in the manual correct? If they are correct, how are 3 pin case fans connected?

 

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Crickets...... I guess nobody has the GA-Z170X Mobo.
I measured the voltages on one of the headers, with nothing plugged in:

   Gigabyte name    Voltage                     4-pin Fan typical name
1 GND                0V                                   GND
2 Speed Control     6.3V                                  +12V
3 Sense            10.45V                           Sense (tach.)
4 VCC                5V                               Control (PWM

That does not seem match the "normal" 4 pin fan pinouts described in the links above.

I also looked at pin 2 and pin 3 with an oscilloscope. There is no PWM - the voltages are steady DC.

So what happens if we connect a 3 pin Fan into this 4 pin connector?

1 GND                -------->     1  GND
2 Speed Control  (6.3V) -------->    2  +12VDC or +5VDC
3 Sense     (10.45V)      -------->    3  Tach
4 VCC

That might work if the "speed control" can source the current needed to run the fan, and the 12V fan can run at 6.3V. However, it seems like a bad idea to connect the fan's Tach output to a source of voltage above the power supply voltage for the fan. I have not measured the impedance of the Sense signal (i.e. whether is has any current-limiting)

So there is still no clear answer. Maybe I'll try some more measurements of current levels before trying an actual fan.