r33gtr speedo output

[razzmtazz]

hi

i am trying to run the factory speedometer through the g4x plugin ecu to correct an over speed reading issue

but the speedometer does not respond to the pmw test 

help would be appreciated  

r33gtr running 10-15-23.pclx

[AbbeyMS]

the factory speedometer sees the signal from the output sensor in the gearbox before the ECU. With a little wiring you could rewire the set up to do what your trying to do. Output sensor = ecu - speedometer

 

[razzmtazz]

12 minutes ago, AbbeyMS said:

the factory speedometer sees the signal from the output sensor in the gearbox before the ECU. With a little wiring you could rewire the set up to do what your trying to do. Output sensor = ecu - speedometer

 

Yes it's now sensor to ecu and to ecu to speedo have not driven the car but the pwm test doesn't work and no sweep also

[Vaughan]

The Nissan gearbox speed signals are a VR type not a hall type so you need to convert the square wave output from the ECU Aux to a VR style signal to make the dash recognise it. I can't remember the exact values of the capacitor and resistor required but there is a diagram of it somewhere in the forum. @Adamw might have a copy of the diagram saved.

[Adamw]

I used the circuit below to make a Nissan speedo work from an ECU aux out.  Basically you need a pseudo "AC" waveform that crosses zero.  I cant remember if this was a skyline or an S chassis as it was several years ago, so no guarantees it will work for an R33, but at least the bits needed should only cost a couple of dollars to give it a try.  

 

Simulated waveform:

[razzmtazz]

Thanks guys for the help it works but muli had to be set at 1.6 for full sweep