Vehicle speed ECU pins (C34, maybe R33 auto too)

[zoomzoom]

I'm working on connecting my ECU to the speed sensors on the C34 stagea, and I'm pulling up a couple of pins for vehicle speed. Just wanted to double check these pins. The wiring diagram says pin 58 is the output shaft rotation speed, which I'm guessing is the speed of the gearbox output driveshaft. Then there is pin 29 which is speed sensor 2. What does this other pin measure? Is it the front wheel speed? I tried to get the info out of the workshop manual, but alas I can't decipher japanese symbols.

[GTSBoy]

In these Nissans the speed sensor in the gearbag sends a +/- 1V AC signal to the speedo head. The speedo head converts that into a 0-5V PWM square wave and puts it out on the line that goes to the ECU, TCU, HICAS CU, etc.