Dakota Digital VSS "Speed Out" for EFI

[Pechin0351]

I know the Dakota Digital VSS has been discussed alot on here. But I could not find a definitive answer for what I am considering.
I have a Mustang EFI, which likes the 8K PPM sensor that produces a Sine Wave. I have a ZF running into a Dana 20. With an American Autowire body harness, and the Dakota Digital HDX. The Dakota Digital doesn't seem to care much what you put into it signal wise, however it comes with a 16K PPM VSS which produces a Square Wave.
Question is this:
Has anyone used the "Speed Out" port on their Dakota Digital box to run their EFI? The Speed Out port can be set to either 2K PPM or 4K PPM and with just an oscilloscope hooked up it seems to be a rather small Square Wave, I have not tried adding a Pullup to see if that does anything to the signal. I am not going to have cruise control or anything like that, just the EFI and the gauge require the VSS, so I figure if the Speed Out signal is enough to make the EFI computer happy, I should be able to run that... Right?
As long as the computer doesn't think I am going over 100 MPH (I thought I read somewhere that it does something with fuel maps or something at that point) and as long as it thinks I am still moving when slowly going down a hill, then I should be good to go. That is where my logic currently stands. Would appreciate any input that might be useful.

 

[SevenT]

Dakota Digital (DD) VSS for EFI

Pechin0351,

I still have not driven my truck yet. But I did piggyback to Ford VSS sensors together on my build. Check Phase 21 build pictures (Post #54) in my build thread. I was told by DD that this would work for VSS for EFI. Fingers crossed.

v/r,

SevenT

 

[Pechin0351]

Pechin0351,

I still have not driven my truck yest. But I did piggyback to Ford VSS sensors together on my build. Check Phase 21 build pictures (Post #54) in my build thread. I was told by DD that this would work for VSS for EFI. Fingers crossed.

v/r,

SevenT

I see that setup. That is an interesting way of doing it. I am very curious to see if that works.

I have been considering the Dakota Digital GPS system for the gauge, but I am also thinking I could just build a simple OP Amp circuit to beef up the signal from the VSS a little. I have read people saying that hooking the ECU and the DD gauge to the same VSS squishes the signal too much for the ECU, which is logical. But If I use a small amp to boost the signal, it might be adequate.

 

[Pechin0351]

SevenT,
I looked through your build thread. It looks like we have both followed a similar path with our Broncos. It was inspiring to read through your thread and see everything you have done so far.

A noteworthy item: I put a 10K pullup resistor to 12V and the Speed Output of my HDX Speedometer box. If I use the supplied 16K PPM VSS and hook it up to a drill, I get a real nice square wave out of the Speed Out port. Its also a solid 12V level (due to the pullup) I do wonder if the A9M ecu can take a nice looking square wave for the input of the VSS.

 

[SevenT]

Dakota Digital (DD) gauge

Pechin0351,

I talked to DD about the VSS signal requirements and they told me to just piggyback the senders and get the 8K signal to the dash and the ECU. I hope it works. I got the idea from someone else here (Blazinchuck) and they had it working. I just hope mine works. Good luck.

v/r,

SevenT

 

[Pechin0351]

It looks like it will work just fine. I just wanted to explore some other options. One sender doing all the work just seems better to me than multiple senders. But it seems like most of the fixes done are either what you are doing, or a GPS Module, or the signal splitter.