RS Fun

[Hitokiri]

Well once we all get a standard piece of hardware and .bins I am going to start work on our JECS ECU.

I have acess to 00 and 99 ECUs so it will be cool to look at how the program changed over the switch from MAF to MAP.

Todd

[cboles]

Since I don't have access to a vehicle with a JECS ECU, can you provide any information on which OBDII pins are use for programming on this unit, so I can help support it in the hardware design? Do you have any evidence that this ECU is reflashable over OBDII?

[Hitokiri]

The unit is most definitely reflashable as I-Speed is currently doing it in secret.

Ecutek has deltadash support for the MY00 and expect that it would work for my MY99 as well.

MY99 was the first year of flash overseas and the start of Ecutek with the reverse engineering of the 99MY ecu. I suspect my ECU to be the first and beginning of the newer select monitor 2 protocol as well as reflashing.

I have a ODB2 scantool for which the hardware ISO line conversions seem to act on 19200 baud. I contunally recieve S S S S S S S and it pauses until it recivieves 6 bytes once it hears one, and the continues with S's at a very high data rate.

I have tried some Init commands to my 99MY and some read bye commands dictated by mumbles' link, but I haven;t gotten a known response. Is it possible that I need a more generic ODB2 - RS-232 line level converter from the one my OBD2 reader uses? (I have been trying to talk to the ecu through it obviously).

I also tried using 4800 baud through it with no success..

ideas?

Todd

[Hitokiri]

I am pretty sure it communicates in sort of the same SSP that the newer Denso ecus do. I have been told that it has much much more in common with the newer Densos than the older JECS from MY98 and older.

Pretty sure it communitcates across the K-line just like the newer

[cboles]

Thanks for the information. I'll try to help where I can. Unfortunately, I don't have a car with one of these ECUs. I can vouch that the 2002-2005 WRX Denso ECUs respond to the SSM protocol at 4800 baud over the K line with no special initialization.

Reflashing the 02/03 requires a 200ms pull-down pulse on pin 9, which then switches the ecu to 9600 baud and a different protocol. Similarly, after an init sequence at 4800, the 04/05 goes to 15625 baud, but uses the same protocol. My point is that perhaps some init sequence is needed to get you unit into the SSM mode.

Do you have DeltaDash? What does it do for your ECU?

[Nemis]

http://kaele.com/~kashima/car/s-ecu/

here some info on "old" ecu.

[Hitokiri]

well its tough to tell. I have nothing to sniff although I do have a good scope if someone around boston would lend a hand with a DD.

Well I suppose your hardware will be able to switch baud rates and supply init voltages, and since we are open source I bet we will be able to figure out in time what the deal with RS ecus is.

I wish DeltaDash was supported for my car. And I would probobly buy it regardless of my ability to figure it out for myself. I know they have support for the 00RS and I have asked for MY99 support or if it would work on a MY99.

well see.

Todd

[west_minist]

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[rsk135]

I know this has been beat almost to death but I still have some questions as I'm new to this.

I have a MY00 USDM Forester, which is basically the same as the Impreza for argument sake. I'm trying to figure out how people are doing the reflash on these. I know there are N/A RS Reflashes out there, like Yoshi in Canada and now I-Speed. Are they reflashing on the K-Line or using the SSM designated lines? I've attached pinouts of a MY02 WRX and MY02 Impreza OBD for reference. Previous years seems to be the same for the Impreza

Colby, I know I can buy a generic cable but i'm wondering if the WRX cable would be better just in case.

Anybody have any ideas?

[cboles]

The OBD connector may be the same, but the ECUs are definitely completely different, so I doubt any of the reflash methods I'm using on the 02+ WRX would work on a 00 RS. Can you post a pinout of the 00 RS OBD connector instead? Unfortunately the ISO-9141 interface is the easiest part of the overall reflashing problem. It's figuring out what to communicate over ISO-9141 that is tricky...

[rsk135]

The pinout I attached for the 02 impreza is the same as the 00 impreza. I think all N/A SOHC are the same. I looked at my car and while the wires are different colors it all seems to match up for pinouts. I have forester specific diagrams coming.
I have also inquired to the developer of the I-speed RS reflash to see what line he is communicating on. I doubt he'll tell me.

Maybe look at this post here's the backup info i found.
http://forums.nasioc.com/forums/showthr ... sh+i-speed

I email Jared@HEMperformance.com

We'll see i guess. Like I said before, I barely understand this stuff and you guys all seem like super-geniuses. I'm just trying to help get some better info out there.

[rsk135]

This is the reply I got.

It uses ISO 9141 protocoll (same as the SSM). It is very similar to the WRX as long as you can figure out what to say. That's about all I can say. Sorry I can't be more helpful.

Jared.

[Hitokiri]

the RS ecu seemes to be the same processor as all GC JECS ECUs namely the Mitsu M32150 processor.

if we can find any utilities developed for this processor we should be able to play around.

anybody know if IDA or another dissasembler supports it?

[west_minist]

Hitokiri,

Did you had any luck w/ the JECS programming?

[Hitokiri]

Well not personally, but I sent colby an ecu. Lets hope that he can work some magic with it.