How many items can be connected to the port? I have a scan gauge connected now but have read a couple of articles on things that would be nice if able to connect. Items such as the paddle wheel shifters from BPD I think it is. Or the turbo brake kit that someone is selling. Everything seems to go to the 1 port, also the use of the other AM monitors go there so how many things can be connected and used?

 

Not from personal experience, just from reading what others have tried: things get flaky when you try to Y more than one thing into the ODBII port. Now if you have something that "manages" the comms., say like adapting a fuel pressure sender to a DashBoss or maybe EGT to DB, that works...

 

The tap shifter does come with a Y adapter for the obd2. My edge CTS gets along ok with it, but they are alittle quirky at times from that. Random and occasional cts turning off comes to mind.

 

I have a dual splitter OBD II cord and have been trying to hookup a Edge Evolution and a Torque Pro unit. I tried this today on my Samsung phone with the light version and while it does work the Edge unit goes bonkers once a minute or so. I did try different communication speeds on the BAFX unit and had the same results.
I would really like to keep my Edge as it has EGT on it.

I will keep trying and post any results.

I hope this info helps.

Rob

 

This is an interesting subject and I've spent a good bit of time researching and still don't have a definite answer except to say "maybe". Here's some stuff I think is true, feel free to correct me if you know better

There is more than one data bus running on the truck at all times, at least three, I suspect several more than that. The OBD connector provides discrete access to at least two of these buses directly through the pins, others share connection pins. Some data (like a temp or pressure value) you may want to read is on more than one bus at the same time, other data is exclusive to a particular bus. (That's where the "maybe comes in")

In order for your device to talk to the trucks computer(s) a connection (handshake) must be established that includes the language they will talk (protocol) and the speed they will talk at. The protocol is not negotiable on the trucks end, the device must speak the language of the truck or they just sit there looking at each other. but they (the truck and the device) will negotiate speed. In computer based software you often have the option of selecting a specific speed and the truck says "ok" or "no", A simple plug in device will auto detect the fastest speed both devices can run and agree on that speed.

So back to the question of the Y cable. Once a data bus has connected (handshake) it will ignore any other requests from other devices, so if the first one connects to CAN HI, the device on the other side of the Y cable can connect to CAN LOW, if that's what it asks to do. Some devices may ask for CAN HI, get no response and stop there so connection is a fail. Some may switch and try CAN LOW, boom! Two connections. It depends on how the device operates, the truck will react the same every time because the interface built into the truck meets the minimum requirements of the CAN specification and doesn't have a bunch of extra features. The device will have to renegotiate and if the designers of the device knows the data they need is exclusive to a particular bus, they're not going to design it try a different bus.

Another consideration is that the busses carry different data. Some particular data points (again, like a specific pressure or temp) may be on more than one bus but some others ARE only on one bus so if both devices require the same data only one will connect, whichever one asked and connected first, the other will be shut out. Connection fail.

So what if the device manages the connection on the truck end and handles both connections on the back end, sort of a OBDII "hub"? This seems entirely possible but I've looked everywhere and haven't found any. The closest I can find are stand alone heads up displays that claim to be able to get their necessary data AND allow another open, fully functional OBDII connection. There is no technical description on how this works but I suspect the data for the display is pulled from a lesser used bus, allowing the main ones to remain open and they figure you'll never notice because most of the common devices will work.

One Last thing I've seen with the Y cable is some describe their product as a "hub", interesting. If you read the technical info though, it turns out these cables have 16 pins on the truck end and 9 pins on the device ends. You're effectively forcing each device to a different bus and avoiding conflict that way. It depends on which data the device needs if this will work for you, and if it doesn't work, swapping them around might make a difference.

I hope this attempt at a simple explanation helps, like I said at the beginning, two devices? maybe, it could work for you, they only real way to know is hook it up and try it. I will say failure is more likely if both devices have a lot of features and functions, the more specific each one (or at least one of them) is, the more likely they are to work together.

Off topic a little but in my internet roaming I did find this little deal. How about 20-30% more power and mileage with an active tuner that custom maps your diesel for only $5.50 (+shipping) What a bargain! I think I will buy me one! Lol

https://www.obd2buy.com/en/obd2-tuni...and-drive.html

 

Been there done that.
The SGII does not play well with others at all.

Rusty you did a good explanation of the system I think.

At this point I would ever use that "Y" again is to lessen the
stress of plugging and unplugging things into the port. When
the "Y" starts getting weak pins I can just toss it out and get a
new one. The Port it's self is more work to fix loose pins.


Sean <BR>

6.0L Tech Folder

 

Rusty good explanation. I figured something like existed, but there are several products that would be nice to add but to buy and try is just tooo much $$. Guess until they figure something out to make them viable other ways just have do without.

 

Great explanation in plain english, Rusty! I tried to rep you but am still in a holding cell