Superfan

I've been working writing my own scan tool to interface via the OBDII port for the RX-8. I bought an ISO interface card that allows me to communicate via my laptops comm port. After some initial testing, I figure that current scan tools will not work. Thing is the RX-8 communicates via the CAN protocol. So now I'm trying to get my hands on every CAN document I can find. If anyone has any documentation or info on this protocol please PM me. I'm just trying to gauge how much time and effort this project will require as I’ll be working on it on my spare time. Initially I just want to read data from the car (temps, rpm, etc..). After that is as close to bug free as possible, I'll try to add the ability to write to the PCM (Adjust fuel maps, timing, etc..). Two guys from the forum have already expressed their interest in helping out with the coding (Sorry I haven't PM'ed you guys back) so hopefully we'll get something going soon. I've already completed the comm port routines in .NET Managed C++ so for now I'll try to get the GUI going until I get more info on the CAN protocol.

Here some pages on CAN and the RX=8:
http://www.etools.org/files/public/C...ear_3-6-03.htm
http://www.etools.org/files/public/g...s-02-17-03.htm

B-Nez

There are some books on Amazon.com. I found this one linked from some site (I've been searching around, too):
Controller Area Network
There are a couple of others - search for the full acronym.

Zoom2X

Take a look at this site. They seem to have a lot of tools (hardware interfaces and software) for vechile ECU development and diagnostics but I bet they aren't cheap. You might want to get a quote tho, no use reinventing the wheel.

http://www.vector-cantech.com/produc...agnostics.html

syntrix

Neither of these tools can see the car's ecu or connect properly:

Vag-com - Full Registered version

Alex Peper's obd-2.com tool

BOOSTD 7

What can I do to help with this VERY intriguing project? Would you like me to sticky this thread?

syntrix

Please do!

Now, does the engine have to be running.... I just turned the key on, but didn't start like almost every other car out there.... worth a try later tonight again.

Of note: The emissions states "OBDII Certified", but the connector port is missing a pin where the 12v+ connector should be.

syntrix

second link from the top, this is probably why most tools won't connect:

60%-CAN 40%-ISO 9141

Grrrr.

Zoom2X

Found this list of OBDII Scan Tools.
http://www.obdiicsu.com/ScanTools/ScanTools.asp

From the above list
http://www.drewtech.com/Products/Cat...ardaq2534.html

This tool can reprogam also.


Might get one of the Autoxray scanners for my home use. Quite a lot of bang for the buck.

rpm_pwr

Alternatively,

Crack the ECU open and look at: CPU and ROM (if any). If you can get me the part #'s off the top of those chips I can find out how to re-flash them directly. All you need then is for someone to get a dump from the 247HP JDM roms.

-pete

syntrix

So where exactly is the ecu? Sorry, haven't had the car for long, especially over a weekend where I can start looking for things .

mikeb

ecu is under the hood to the left and by the headlight it has a plastic cover over it like everything else

astrlsrfr

Here's what the ECU looks like. Chip #s follow.

astrlsrfr

I think this other board is related to the suspension, since the housing said "Showa". But, I could be wrong.

astrlsrfr

.

astrlsrfr

The chip numbers on the actual chips are extremely fine & small. You can only read them if the light hits them just right. These numbers are only from the main board. Be aware that "5s" could actually be "Ss" - its that hard to read em. Also, these are only the larger chips & I could have missed some numbers even on these chips.

Anyways, I put my best guess as to the chip's function in parens. Hopefully some hardware-based EE can help us figure it all out.

D151815-8550 / SC 515611MFC185

64F7055F40

D151821-1280 (RAM?)

SPF00001 / SK3206 (Surface-mount Power Transistor Array?)

SE585

3E19 SE555 (timer?)

MC 331 (CPU?)

blizz81

It would be nice if you could compare dumps from both, ie with software interpreting the data and spewing it out in some readable form. This way we could, for instance, see if the only 'emissions change' is the retardation of timing due to lower octane fuel in the US as opposed to Japan, something that I think most owners wouldn't want changed here in the states as far as having their ECU reflashed.

I wish I was a bit nerdier and could get into the discussion more - just a tad bit of assembly and serial communication experience.

OverLOAD

I've got access to a cardaq & interface software, if anyone has a wiring schematic for how to hook up the cardaq to the ODBII bus interface (or a place to get a premade harness) That would help me, I could then get some dumps of the Flash contents..

OverLOAD

Superfan

I found a few CAN Adapters ranging from $2000 to $220. The $220 adapter is USB compatible. That scared me a little since I've never written anything that interface's via a USB port. So I was looking up all sorts of junk on how to enumerate and access USB ports. Then I downloaded the documentation and drivers for the USB Adapter and found it comes with an API. They have every interface a developer could need (vb, c++, delphi, C#, etc...). So I went ahead and ordered it. As soon as it comes in I'll test it out and post the results.

This is the site that sells the USB CAN Adapter:
http://www.gridenabled.com/canboandto.html

BTW: It doesn't come with an OBD-II cable. You have to get that separately.

syntrix

Nice, even a linux driver!!!!

Embed linux on a pda, create the software with the api guide, and go go go!

Sounds like something I'd rather buy than take the time to make

rpm_pwr

hahaha nice work :D

That there is the CPU that runs the show. This is a Hitachi SuperH processor by Renesas(hah!), and an impressive one at that:
You can see the CAN interface for you OBD guys. But it's the flash I'm interested in. I'm going to have a read about this today but straight away you can see the JTAG pins on the block diagram:
http://www.renesas.com/eng/products/...055_block.html
(thats the TCK,TMS,TDI,TDO pins on the LHS) All you need to do is trace those pins to the headers they use for production programming and read it in

-pete

rpm_pwr

What you're asking is no small feat. Gone are the days when you can just trace out a netlist, get the ASM dump and figure out how it does everything. Big (huge for the embedded world) processors like the SuperH often run operating systems (a superH can run Linux for example), so decoding the ASM to find the fuel/ignition maps is an exponentially harder job than it was in the days of the old 8/16 bit mazda ECU's.

Second to this, Japan rates it's fuel using RON whereas the US uses PON, so saying one fuel is better than the other is flawed because they can't be compared. I wouldnt mind betting that US high octane (93?) is probably near identical to Japan's 100RON

-pete

Sparky

Be carefull about purchasing a low dollar CAN interface. The intent of the new interface is to allow real time data logging without use of an oscilloscope thereby reducing the requierment for maintenance aids at dealerships. In short a low speed CAN interface won't work. The best I have been able to ascertain at this point is a data transfer rate in excess of 500 kbs to communicate with the chip. The great part of this is that we've basically got a car that's fully instrumented from the factory!

Superfan

The CAN interface I ordered is supposed to go upto 1MBaud. So it should be capable of High / Med speed CAN. If it doesn't work then my little project is over since I can't afford to buy a $2k CAN interface. Mazda bought 12hp for $500 from me. I'm just trying to buy them back for under $500.

syntrix

Hopefully it works out!!!

Otherwise I might have to take the plunge, but I'll see what others can figure out first.

I'm very mad that my two other obdii tools didn't work!!!

blizz81

There was another real-time CAN device listed in my OBDII/CAN revisited thread in here by someone else. Also I found out from carchip.com that they have no idea when their reader will be CAN-compatible but that they were working on it. Crap, I don't know why I trashed that email, I was going to paste it but trash has been emptied since then.

That's a good thing to keep in mind. But you can understand my concern. I wouldn't want a bunch of people without pondering it over to flash their ECUs with JDM dumps say, in the winter time, and then later find out when the temperature is over 75 degrees, the engine knocks easily and their KS kicks in retarding the timing down to the original degrees in the US ECU, or lower. etc.