Speed Singal From Trans, Squre Or Sine Wave?

[DennisRB30]

I have a R31 and am wondering what type of signal normaly comes from the speed sensor on the trans? Is it a square wave or a sine wave? I am trying to get my speedo to work with my auto 2JZ trans speed sensor.

[(OO_The4door_OO)]

R31 - 99.9% sure it's sine wave.

Not even my R33 speed servo has a square wave output, the ECU just has an op amp sitting on the speed input stage to change the sine to square.

[DennisRB30]

R31 - 99.9% sure it's sine wave.

Not even my R33 speed servo has a square wave output, the ECU just has an op amp sitting on the speed input stage to change the sine to square.

I think it is a square wave. Reason I say this is becuase I tapped into the wire at the dash cluster and hooked a multimeter up on DC. If I roll the car along very slowly I can see the voltage go from 0V to 6V and back again. The faster the car goes the faster it goes from 0V to 8V. Here are some mesurements at the dash cluster. I took them with the speedo connected, so I'm not sure if that affects the readings.

[C_DawG]

Stick it on stands and drag the CRO out, DMM isnt of much use.

[DennisRB30]

Stick it on stands and drag the CRO out, DMM isnt of much use.

Well it may not be as good as a CRO, but you would have to agree that its good enough to tell if its a square wave or not going by my findings. I dont have a CRO.

[PHATR32]

i take it you boys have cros sitting around in the shed??