Autosport Labs

I recently bought a MK3 data logger, and am installing it in a prototype road course racecar powered by a Suzuki Hayabusa motorcycle engine. I’ve got the MK3 installed, but nothing hooked up beyond the power and ground yet.
I’m hoping someone can help simplify some things for me first.

From what I understand, I can tap into each of my sensors on the engine, and passively read the values in the MK3 sensors – at least individually, and possibly through the CAN system. However, I’m hoping I can bypass having to hook up each sensor to the MK3 individually.

The Hayabusa does not have OBD-II. However, it appears it does have CAN - not certain, and not sure how to find out for sure. One particular wire goes from the ECU to the diagnostic computer and is labeled SDS/SDL depending on the end of the wire you are on, and another wire that goes from the ECU to the dash unit labeled data/tech, again, depending on the end of the wire you are on. I don’t know what data those wires carry.

I believe everything on the engine (as far as sensors is concerned) is 5V.
If either the Data or SDS/SDL wire carries the data I need, how can I tell or determine what it does carry?

What I'm hoping to do is tap into either the DATA or SDS/SDL wire and be able to access all of the data that way rather than via individual sensors. From what i read, it can be a pretty big ordeal trying to accurately set the parameters for each sensor in a non-laboratory environment.

I will be very appreciative of any info you can give me – on the above questions or anything else you think might help.

The above is the original post. After that post, I did a little more looking, and have additional information that might help you - which you can see in the schematics if there is a way I can get the schematics to you. There are two diagnostics plugs. One is for flashing the ECU. The other one is "SDS". I think the SDS plug is for reading the data, but not sure.

In the SDS plug, there are only 3 wires that go to the ECU editing program - 12V+, ground, and SDS. Within the ECU editor program, you have the capability of reading gobs of data. Thus, something in there has to be a CAN wire of some sort. The question, is it a CAN that is compatible with the MK3 software? Then, if it is, how do I use it? From what I understand, CAN has to have a "high" and "low". I would assume the SDS wire would be the "high" wire. Would it be safe then to assume that the ground wire (which is a common ground for the engine) is the "low" wire?

On the "flash" plug, two wires were added for flashing (not factory), and only two of the factory wires remain, going to the ECU Editor. Those wires are labeled "RXD1, and "TXD1". I assume those are communication wires (transmit and receive), likely for communicating progress of flashing, but not sure.

I'm planning to get started in the next couple days with the setup. It would be great if I go into this with a little more information than i have at this point.

The file of the schematics is too large to attach to this message at about 723KB. If you feel the schematics might help, please let me know, and let me know a way I can send it to you.

Thanks.

Hi ProtoTim35,
from your description the communication isn't related to CAN, sorry.
CAN uses two wires, as you mentioned by yourself. Therefore when you have three wires being 12v, GND and one more wire then for sure this can't be CAN... SDS (Suzuki Diagnostic System?) is most likely using a proprietary serial protocoll. From a quick google search it seems to use a KWP2000 K-Line protocoll, however there isn't all of the details available to the public, and I think digging into this by your own and make it work with RaceCapture will not be an easy task as is.
In addition this KWP2000 has pretty low update rates (talking about the data that you would receive per second) and depening on what you are trying to achieve in general with the RaceCapture unit the data will simply be too slow to be really useful after all.

So three options that come to mind:
1. search for all the information out there and then you are still only at the beginning where you will see IF it is possible at all to write some special code and need someone that may code something for you ... I think this will not work pratically and is a waste of time in my opinion.

2. tap directly into the already available signals and/or even use a second set of sensors for some of the things you want to have in RaceCapture. This is possible however be aware that there is still some risk of accidentially messing up sensor signals to your OEM ecu in case you do it the wrong way. Having redundant sensors has it's pros and cons

3. You could buy an ecu bridge from AIM which can be configured to read data from the SDS wire... this ecu bridge can output data in a CAN format that would be readable by the RaceCapture unit, because parts of the AIM stream are well documented within the AutosportLabs group. There is still the possible drawback with low update rates with this way of doing it.

Of course the "best" way of doing it depends on your own needs, the work that you want to spend and the money... I think option 2 is the best when you want to simply have data being received at a high update rate.
And you can always add something like the ecu bridge I was talking about when you want to see the values directly from the engine management (either for diagnostic purpose or direct use). So start with direct sensor connections or ecu bridge depends on your preference

Regards,
Mike

Hi again Mike,

Thanks again for getting back to me. I appreciate your help on this. I've already set up most of the sensors through analog, as you recommended - I did that last week. I used the factory sensors, and used the MK3 for getting the voltage parameters - at least good enough for what I need to do with it - since I couldn't find anything published anywhere on any of them.

As you said, it was a bit of work, but I have most of them pretty well squared away. Still working on the O2 sensor - That's a bit of a story, but I just ordered a wide-band sensor and controller that I will hook up as soon as it comes in. Otherwise, the only two sensors I need to tweak are the TPS, which I'll do at the track, where I can read the voltages for idle and WOT on one run, and set the parameter then into the MK3, and see how it works. I already tried it with the engine shut off and ignition on, and set it up based on those readings. Unfortunately, when I started the engine, the scaling was way off. Consequently, I'll have to get new numbers with the engine running. In fact, I found that most of the sensors were like that. I had to set them up with the engine running, not just with the ignition on. With just the ignition on I would either get screwy readings, or the readings would change a lot when the engine was running. The other sensor I would like to tweak is the gear position sensor, which we discussed in another message.

Through further research, I found (as you said) that SDS is for Suzuki Diagnostic System.

I am interested in the K-line bridge you mentioned. Where can I get more information on it. As you said, if it's as slow as it sounds, I probably wouldn't use it for much, but it might be useful if it isn't too expensive, and isn't too much trouble to install.

I'm learning more about more things in building this car and everything associated with it than I had ever anticipated. I love learning, but it can be so time consuming sometimes through all of the research and learning curves that it can sometimes feel overwhelming. I greatly appreciate help when I can get it. This has been a very intense 7 year project that I started out thinking I was going to be able to complete in less than a year. I'm now only days away from having it track ready. The data logger has been a big part of the hold-up for the past couple weeks. I thought I could have it set up in a matter of a a few hours. I've probably got at least 30 or 40 hours in it at this point. That isn't just the data logger itself, but including trying to figure out how to set things up - especially the O2 sensor, which I think I now understand a lot better after all of the research. Hopefully, now that you are helping, you can help me finish a few things up. I'll be glad when the data logger is squared away. I really appreciate your taking the time to help me.

Thanks again.

Tim