Subject	60mph is displayed when the speed sensor rpm is 1024.
Posted by	DVDBURN (MD) on May 28, 2020 at 1:08 AM
	This message has been viewed 188 times.
In Reply To	'91 Z32 Speedometer Bench Testing posted by charleyd on May 23, 2020 at 03:48 PM
Message	The speed sensor is a wave forming circuit that produces an output signal in hertz (SI) via two wires, ground and signal out. The speed sensor generates 16 pulses per 1 rpm of the speed sensor. 1 RPM = 0.0166666666666667 x 16 = 0.2666666666666672 Hz 60 mph = 0.2666666666666672 x 1024 = 273.0666666666672128 Hz 60 mph = 273.0666666666672128 Hz (Input drive signal to equal 60 MPH) 1 mph = 273.0666666666672128 / 60 = 4.5511111111111202133333333333333 Hz (2P output signal to ECU at 60 MPH) The 2P output signal to the ECU is the speed sensor signal divided by 8 and converted to a DC square wave. If using a scope to measure it you won't see it if the gauge is not connected to the ECU. You'll need to use a pull up resistor. 2P = 273.0666666666672128 / 8 = 34.1333333333334016 Hz @ 60mph. www.mytwinturbo.com Nissan Data Voice - The first Nissan diagnostic software with a voice! Nissan Data Voice on YouTube Download my Nissan 300ZX Vin/Model Lookup.
Follow Ups	'91 Z32 Speedometer Bench Testing - charleyd 15:48:05 05/23/20 Member DVDBURN is a guru with speedos (n/m) - ctheobal 18:17:30 05/23/20 Re: '91 Z32 Speedometer Bench Testing - scorp997 13:30:23 05/27/20 60mph is displayed when the speed sensor rpm is 1024. - DVDBURN (MD) 01:08:33 05/28/20 Re: 60mph is displayed when the speed sensor rpm is 1024. - scorp997 02:47:15 05/29/20
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