987.1 Can Bus Mapping

Discussions on CAN mapping for ECUs, sensors, PDMs, and more.
stephen
Posts: 10
Joined: Wed Aug 22, 2018 2:32 am

Post by stephen »

Big thankyou to you guys for sorting the CAN for the 987.1. I thought getting the steering would be good but you've also got the brake pressure giving me plenty to look at.
[/img]

VPD
Posts: 36
Joined: Sat Aug 11, 2018 1:40 pm
Location: NC

Post by VPD »

boggie1688 wrote:Sorry yes oil temp is there. It has been ages since I worked on this. I think Brent made my configuration available. You should be able to just load it an go. Otherwise download the zip and use the config there.
I got my RCT2 installed and used your presets to get a jump start. I've found a few discrepancies from what I've mapped previously, so I made some changes and am still playing around. I've connected both the Drive bus and the Display bus (my previous posts incorrectly called it Komfort, I'll fix that) and will be adding more channels as I go. Once I'm convinced I've got good data I'm happy to share back.
For the pressure I just added a sender to the motor. I found one on Amazon and just wired it up. There is a galley port on the driver side of the motor towards the rear of the car. It's a real pain in the ass look get in.
As I alluded to in an earlier post, I had an idea to try for oil pressure and it was successful. I ended up buying RCT instead of RCP because I was able to inject oil pressure CAN data onto the Drive bus and avoided RC analog inputs.
Brake is definitely there it responds to the brake pedal and I actually think it's pressure. It doesn't scale according to travel, but how hard you step on it. It's just slooooooow. It looks like you ate left foot braking in the logs.
I briefly played around with this and found I have a very quick response, so I have 2 quick thoughts on why yours is slow.
1) in your presets the sample rate was set to...1Hz
2) the scaling may be off (I don't know correct scaling either right now). If the formula has "low sensitivity" then the CAN data might swing around quickly, but the calculated value will stay ~constant giving the appearance of slow response.

boggie1688
Posts: 138
Joined: Fri Apr 07, 2017 3:47 pm
Location: Oakland, CA

Post by boggie1688 »

Love to see the brake stuff as I'm not happy with the slow response I'm getting. Sounds like your making great progress!

ProtoTim35
Posts: 79
Joined: Fri Jun 22, 2018 2:14 am

seeking help/advice with Hayabusa linking

Post by ProtoTim35 »

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.

brentp
Site Admin
Posts: 5956
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Hi,

Thanks for the post. You should create a new topic, since this is different than this topic, discussing Porsche CAN mapping. Thanks!
Brent Picasso
CEO and Founder, Autosport Labs
Facebook | Twitter

VPD
Posts: 36
Joined: Sat Aug 11, 2018 1:40 pm
Location: NC

Post by VPD »

boggie1688 wrote:Love to see the brake stuff as I'm not happy with the slow response I'm getting. Sounds like your making great progress!
The brake channel is working fine and the scaling is simple. I don't recall what you had but this is correct and responds fast. I confirmed pressure values using Durametric simultaneously with RCT.

CAN ID 1099
Sample rate 50Hz
Offset 0, length 1
Scaling x1 /1 +0 (essentially no scaling) giving pressure in bar
Use the conversion feature bar->psi if you want

By the way, do you have PASM? While brake pressure is on the Drive bus I found Durametric polls it from the PASM suspension controller. I have an aftermarket controller installed and couldn't see pressure until I swapped the factory controller back in. This makes me wonder if cars without PASM don't have brake pressure data.

I'm still struggling to 100% identify the throttle plate ID/byte(s). I see the pedal position data duplicated on 242h and 246h, but nothing clearly the plate. I thought byte 7 on 242h might be it but it acts strange if it is. Really need plate to see if the ECU is reducing power due to traction control or mods exceeding the torque limits in the calibration.

boggie1688
Posts: 138
Joined: Fri Apr 07, 2017 3:47 pm
Location: Oakland, CA

Post by boggie1688 »

Interesting question and hypothesis!

I don't have PASM.

1099 offset 0 is exactly what I have mapped for my brake. I'll try upping the poll rate and see if that fixes it. My next autocross is not for awhile, and there is some other general maintenance that needs to be address. I'll report back! Thanks for confirming!

stephen
Posts: 10
Joined: Wed Aug 22, 2018 2:32 am

Post by stephen »

I don't have PASM and am getting useful Brake pressure readings. I didn't think it had much lag either though it does have a bit. It's good enough to show me I need to work on brake sensitivity. Though scaling might be off, <100psi max seems a bit low for braking system.

VPD
Posts: 36
Joined: Sat Aug 11, 2018 1:40 pm
Location: NC

Post by VPD »

stephen wrote:I don't have PASM and am getting useful Brake pressure readings. I didn't think it had much lag either though it does have a bit. It's good enough to show me I need to work on brake sensitivity. Though scaling might be off, <100psi max seems a bit low for braking system.
I would recommend using the scaling I showed above and double check that you are using the built-in units conversion function (bar ->psi) on the last tab in the channel setup. With the engine off pressing the brake pedal really hard a few times gave me 60 bar = 870 psi.

boggie1688
Posts: 138
Joined: Fri Apr 07, 2017 3:47 pm
Location: Oakland, CA

Post by boggie1688 »

Have either of you tried to datalog while either on a track or autox? The lag I'm describing was not noticed until using racerender to overlay the info. There was a definite overlap between throttle and brake transitions, almost like I was left foot braking.

I may or may not have logs that date that far back. I'll look tonight and see if I can get a screenshot of the two data. Curious to see if you guys see the same.

VPD
Posts: 36
Joined: Sat Aug 11, 2018 1:40 pm
Location: NC

Post by VPD »

No problem on track either. I just grabbed a random lap and attached a screen shot. I have not used RaceRender, but using the built in RC Analysis screen everything is in order.

Accel X, Brake (pressure in bar), and Brakeonoff (brake light signal) are all properly aligned, and placed in time correctly just after Throttle (purple) hits zero.

You can see the brake pressure trace contained within the yellow square wave of Brakeonoff. Due to the significantly different sample rates, you can also see the Brake (50Hz) trace sometimes starting just a hair before the Brakeonoff (10Hz) which is physically impossible.

I think your brake channel was set to 1Hz, which is an eternity in terms of brake pressure build up in a hard, deep braking zone. In this screen shot it goes from 0-60 bar in 0.47 seconds.
Attachments
Brake Pressure Trace (bar)
Brake Pressure Trace (bar)
Brake Pressure Trace2.jpg (254.63 KiB) Viewed 185 times

boggie1688
Posts: 138
Joined: Fri Apr 07, 2017 3:47 pm
Location: Oakland, CA

Post by boggie1688 »

Hmmm... Good deal. I'll play with that this weekend! Thanks.

boggie1688
Posts: 138
Joined: Fri Apr 07, 2017 3:47 pm
Location: Oakland, CA

Post by boggie1688 »

Happy to report the polling rate may have been my issue. :P

Well see at the next event.

Shame shame shame on me.

TimG
Posts: 2
Joined: Sat Jan 05, 2019 6:23 pm
Location: Virginia

Post by TimG »

I just received the RaceCapture/Track kit and am looking for some assistance with my 991.1. I am posting here because I thought some of you might be able to assist with your Porsche experience.

Here is a link to my introduction and 991.1 post
viewtopic.php?p=29201&highlight=porsche#29201

Post Reply