Ecu Speed Signal

[Roy]

I want to use the speed signal that the ECU sees so that i can monitor the road speed with an external device. Does anyone know how it works?

I understand that the speedo cable goes into the dash cluster where the a signal is generated for inputting into the ECU. It would be appreciated if i can get the heads up on how this signal works?

[clakka]

Have a look for a wiring diagram...they're in one of the forums on here just cannot remember which...you just put the wire from the external device onto that wire and Bob's your Uncle but if the speedo goes it all goes (been there done that)...Hope this helps

Edited January 25, 2007 by clakka

[Roy]

Thanks. Problem is the deivce im using isnt supplied with any programming to interpret the signal. Its a data logger and i want to change fron the Hall effect sensor located on a wheel to using the ECU speed signal.

Which means i need to calibrate the unit to the signal..only i have no idea what the signal is

[ali-turko]

when i installed my pivot speed metre on my gtr, all i did was cut the speed sensor cable on the ecu and wired it up there,

hope that helps

[boot_it]

I want to use the speed signal that the ECU sees so that i can monitor the road speed with an external device. Does anyone know how it works?

I understand that the speedo cable goes into the dash cluster where the a signal is generated for inputting into the ECU. It would be appreciated if i can get the heads up on how this signal works?

pinout 53 is vehicle speed sensor and its colour is yellow with a green trace

[Roy]

But the speed meter knows what the signal is as it would be made for the NIssan ECU.

Oh well, looks like i get to do this the hard way...with a laptop, a weekend and a speed camer

[khunjeng]

if ur using the ECU speed signal I though the sensor would be the same a wiring any piggyback/safc/rsm.

Not quite sure what u wanna do but the Hall Effect Transducer assuming u have an IC with Schmitt triggers will give u a +/- 5V output anyway.

I assume the speed cable into the ECU will be the same.

This would give u a voltage output and u can interp. anyway you want. As far as I can remember they are linear devices so check some speeds and record the voltage and graph it up...would give u the conversaion. Not sure how accurate, but would be ok.

Done it a few times for speedos in yachts...hallf effect transducer is the only thing in a package they usually sell for $500...IC costs me $5 at most.