VSS Input Voltage

K-Series Programmable ECU installation questions / support issues
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clsladek
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VSS Input Voltage

Post by clsladek »

I am trying to run the signal from my E30 cluster which im pretty sure is a 12v square wave form. Is 12v ok to run to the Kpro VSS input or do i have to find a way to convert it to a 5v signal?
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Hondata
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Re: VSS Input Voltage

Post by Hondata »

Probably not a good idea. The KPro input is protected but there is a pull up to the ECU 5V so you will start to put a 12V waveform on the ECU 5V supply.

It really likes an open drain input where the input will ground the KPro Vss input. Hence the 5V pull up.
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clsladek
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Re: VSS Input Voltage

Post by clsladek »

Any idea the best way to convert this input to a usable speed signal input?
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Hondata
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Re: VSS Input Voltage

Post by Hondata »

A resistor and transistor as open drain will covert the signal. There may even be pre-made modules to do this. Selection is up to you however - I'm just here to tell you it needs to be 0-5V.
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clsladek
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Re: VSS Input Voltage

Post by clsladek »

Hondata wrote: Sun Aug 29, 2021 11:34 am A resistor and transistor as open drain will covert the signal. There may even be pre-made modules to do this. Selection is up to you however - I'm just here to tell you it needs to be 0-5V.
will the ECU have trouble if the voltage is below 5v? like if it fluctuates between 3.5-5v but still grounds to 0v will that still work?
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Hondata
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Re: VSS Input Voltage

Post by Hondata »

It should be < 0.5V and > 4.0V for every pulse.
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DriverMikeD
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Re: VSS Input Voltage

Post by DriverMikeD »

Ever find a off the shelf solution for this?
Jakermac
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Re: VSS Input Voltage

Post by Jakermac »

DriverMikeD wrote: Tue Nov 22, 2022 8:45 pm Ever find a off the shelf solution for this?
I'm wondering if this will work. I'm looking to feed the E36 VSS signal to my KPro in a PRB ECU.

https://www.diyautotune.com/product/axm ... LrQd4Ls1zA
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