achipfef

Hy all

i just need to know if the square wave signal (VSS) off the pcm is negative or positive ???

The speedometer gauge i want to buy need a negative square wave signal

Thanks
Achim

KCS

iTrader: (20)

Let me move this to a more appropriate Section.

mrvedit

Since our cars only have a +12V source, any square wave signal (actually any signal) will oscillate at most between 0V and +12V.
It could be that they are referring to either a specific duty cycle (unlikely) or that it triggers on the negative part of the square wave as its voltage drops from +12V to 0V (which is an unimportant detail to us).

Why not just tell us which Speedometer it is; someone may have used it.

achipfef

thanks for that information....

I am from Germany....so the dealer is also located in Germany...
nevertheless here is the link for the speedometer

https://www.mmb-messtechnik.de/index...category_id/25

I will get in contact with the dealer once again to clarify that "negative" point

Cu
Achim

mrvedit

Since I am originally German and almost fluent, I had no trouble reading the description. Nowhere does that page say anything about "negative". It mentions this is the 12V version and a 6V version is available.
It does say it is compatible with factory Harley Davidson sensors - I just checked their forums and it appears those bikes use a Negative ground just like our cars.

achipfef

perfect u can read german ..thats good for me :-)

i am a newbie with stuff like that....a few weeks ago i spoke with the dealer about the speedometer.

He told me that the speedometer need a "Rechteck - Signal (negativ geschaltet)"

I have no clue what he meant with "negativ geschaltet"

Currently we have a public day, so i cannot get in contact with the dealer.
I gonna ask him next week.

Generelly they also use the speedometer on bikes with a hall effect sensor.

So i hope it will work , cuz the design of the gauges are pretty cool and fits perfect to my chevy pickup

I come back after i spoke with the dealer

Thanks
Achim