The AUSubaru.com.au Forums

Going to use max232 as the easiest method of getting TTL to RS232 comms, have used it for comms on my programmable delco ecu. Had already looked at the openport cable schematics etc but have not found one that supports ODB II pins 12/13 ie no SSM capability. The more I read, the more I get confused ...

Have oscilloscope, another long story but now in business. Only had time so far to confirm data coming out of the serial port when vwrx or ecuExplorer software is running. Rates look similar but detailed analysis to follow. Think the big issue is my interace inverts the data, my mistake. Need to re-...

Pick up replacement oscilloscope tomorrow morning and then can see what is going on. Have tried ecuExplorer & vwrx software, neither work, even sent ssm initialization word direct to ecu without success. Need oscilloscope!

Strange number but if it works who cares As I said don't known what vwrx software does & no mention of a setting that I can find on his webpage. Will have another look & perhaps send him an e-mail for clarification.

Was similar to the "discrete device" one on vwrx.com web page. Simple level shifter, TTL to RS232 each way. Seems too simple to be true but his recommendation for his software, so worth a try. Also, further to what daza said, have found some info on ssm protocol that says ssm uses UART settings 4800...

Suparoo, now in your situation. Built interface to support vwrx.com ssm software but did not work & just to ice the cake my oscilloscope blow up before I could do any testing.

Will have to wait until replacement scope arrives.

Another suggestion, may be the adpater need handshacking. The vwrx software uses a level translator & no handshacking. Your adapted may need it to function.

Another suggestion, I'm full of them, do a loop test on your usb/ttl adapter, connect tx to rx.

Been doing so more research into OBD II for oz cars & most sources claim that imports from 2002 could be compatible, oz build from 2004 could be & all oz cars after 2006 must be. USA cars from 1996 had to be OBD II but Subaru might have built special non OBD II cars for oz. Suggests that my Impreza ...

Suparoo you have been busy, hense my comment "not my intention to offend". Only thought is have you tried crossing Tx & Rx connections.

Have scope & know Bowraville well but a bit far from the Blue Mountains. Have you confirmed that the SSM signal wires actually appear at the 9 pin connect. I suspect they do not as I have belled my cable with the following results: OBD/D9 16/9 15/8 14/5 10/6 7/4 6/3 5/1 4/2 2/7 No 12 or 13 which I b...

Suparoo, been doing some more investigation & if you have the same OBD II to DB9 cable that I do, then SSM will not work because the appropriate connections are not passed through. Makes sense as the cable was sold as ODB II not Subaru SSM. Will recheck to confirm & if I cannot get OBD II to work wi...

Your TTL/USB adapter is a buffer/level translator. The TX SSM signal should feed into the adapter Rx pin & the Rx SSM signal does to the adapter TX pin. GND goes to GND. The +5 is not needed. The USB driver s/w should be loaded and configured for a virtual serial port for your SSM s/w. Not my intent...

Have I got the config correct: vwrx.com SSM s/w & TTL/USB adapter s/w loaded, TTL input pins on TTL/USB adapter connected to SSM pins in OBD2 connector & USB output to pc.

More ramblings from the novice. Just so we are on the same page. The package you have has s/w that gives you SSM & OBD2 capability? You can get it to work on the Outback in both modes? But will not talk to the Forester in either mode?

Accept that I am a novice and therefore my interpretation of the info I have may not be valid, but from what I have read about the L line it is required for the interface. http://forums.openecu.org/viewtopic.php?f=4&t=1225 . It also appears to be used in the ELM327 chip that I assume is in your inte...

My ignorance is shown by your explanation of the Subaru/OBD2 connector difference, I am only a beginner at Subaru ecu tuning. Prior playing has been with GMH Delco ecu tuning. I have a logging program & an interface cable with H/W that uses pin 15 (ISO L) of the standard OBD2 connector. At this stag...

Sorry, the formatting was lost in the post, here is the info again.

Subaru
1 power
4 select monitor
5 select monitor
6 line end check signal
10 K line
12 GND
13 GND


OBD2
4 GND
5 GND
7 K line
15 L line
16 Power

Have yet to confirmed on my car, is to be the next step. If this info is correct & you plug in a standard OBD2 scanner into the Subaru OBD2 connector you could suff the "select monitor" section of the ecu. Terminal Subaru Function OBD2 1 power 4 select monitor GND 5 select monitor GND 6 line end che...

There is a click when I press the accelerator to the floor but this did not help & I thought the down change control on an electronic auto would be more suttle than a simple switch. Would expect the engine load conditions to dictate the auto action, why else would the MAP sensor signal be fed to the...