PCM signal for speedometer ??
Thread Starter
Teching In
Joined: Jul 2014
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PCM signal for speedometer ?? 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
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
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Joined: Aug 2010
Posts: 7,323
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From: Ann Arbor, MI
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.
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.
Thread Starter
Teching In
Joined: Jul 2014
Posts: 33
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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
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
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
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.
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.
Thread Starter
Teching In
Joined: Jul 2014
Posts: 33
Likes: 0
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
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
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.
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.
