Programming Ourselves?

I think their DLL probably does support all the functions. These are the functions that need to be implemented for J2534:

PassThruConnect
PassThruDisconnect
PassThruReadMsgs
PassThruWriteMsgs
PassThruStartPeriodicMsg
PassThruStopPeriodicMsg
PassThruStartMsgFilter
PassThruStopMsgFilter
PassThruProgrammingVoltage
PassThruReadVersion
PassThruGetLastError
PassThruIoctl

I was expecting the J2534 spec to be a 500 page document, but actually it's only 50 pages or so. Surprisingly enough, there really aren't that many functions, and I'm not sure you could get away with not implementing any of them (maybe PassThruReadVersion, because that only returns info about the DLL itself).

Actually, it only now occurs to me that you said you downloaded the drivers. I think I'll download it later too and see what functions it actually does export...

 

Ok, I disassembled op20pt32.dll which is Tactrix's version of the J2534 DLL and it does indeed implement all 12 functions I mentioned... And two more PassThruOpen and PassThruClose... Huh? Maybe I have the wrong version of the spec.

Oops, my bad. Yes, those functions also need to be there. They're used to initialize the connection to the passthru device, and to terminate that connection.

 

Just sent an email to Tactrix to see if they might have more compatibility info.

If they don't, I'll push to see if they might offer a more liberal return policy for someone willing to try it on a Toyota. If they agree then I'll bite, if not I might wait.

The pin 12 voltage gives me some hesitation, although just because Mongoose offers it doesn't mean it's required by Techstream. I'm just not desperate enough to risk $200 to try it...

Any other brave souls out there?

 

Hmm... I want to try, but I also don't want to find out the hard way that it doesn't work.

I'm trying to figure out whether the 2010 uses EEPROM's or flash memory in its ECU's. If the car uses flash memory (which I understand is actually cheaper than EEPROM) then there's no need for the vpp +5 to pin 12. If it does use EEPROM, then there has to be a programming voltage of some sort I would think.

I was also trying to find the common ground between the different officially supported tools on the techinfo website:
https://techinfo.toyota.com/techInfoPortal/appmanager/t3/ti?_pageLabel=ti_j2534_device&_nfpb=true
Unfortunately they're all too vague about the specifics of their devices (except for Mongoose)

I found a post about the older Mongoose ISO/CAN from Joey Oravec who apparently works at DrewTech. He posted this in a thread at mp3car.com:

"Unfortunately it lacks programmable voltage/ground lines which are required to flash certain honda and toyota vehicles. I wish we could add that feature but it's a size/cost thing. Maybe a future product? For now, buy CarDAQ if you need those."

This suggests that the programming voltage is necessary for Toyotas. But... This was written way back in May 2007. I don't know whether he was referring to older vehicles, or vehicles that were just coming out at that time. I also read a post somewhere else that suggested newer cars were moving to flash memory and no longer required the vpp. I don't know how accurate that statement was though.

So right at the moment, it's still a guessing game. I hope they give you good news about the return policy, vkykam. Or at least I hope they let you know when their product will start supporting 5v to pin 12

 

rachaelseven and the other e-smart posters on this thread,

My apologies for being oly tangentially on-topic here.

It sounds to me like you guys and gal can get as much info out of the
HSD and its computers as any Pirus tech. So...

I've been led to believe that somewhere in the HSD or its software
there is a logging function that records all kinds of stuff.
Some potentially useful: max RPMs, speed, and various temps
Some kinda weird: number of times gas pedal is pushed when car in
neutral ??

I think it would be very interesting to see just what values are in
fact logged. I can't find or remember anything like this being posted
here.

If you guys and gal could generate a list of what if anything is actually
logged and available to Prius techs, and then post it as a new thread, I
would think that it would have a good possibility of being raised to
Sticky-hood.

 

Did anyone try if Tactrix OpenPort 2.0 works with TechStream?

If I understand correctly we think it may not be able to write data (flash) to Prius right? Even then, it should be able to read out all the data available in TechStream correct? $169 is still a very good price for the view-only capability. You may be able to run PCMSCAN with this hardware since it is J2534 compliant.

 

OK, I've read through this thread multiple times trying to figure out if I should try any of this stuff. I'm fairly technically saavy...I'm an 30-year aerospace engineer who launches rockets for a living, but unfortunately, this ISN'T rocket science...and I've dabbled in both cars and computers as hobbies.

I'm contemplating shelling out $150 for a tool that only programs TPMS sensors so I can swap out winter tires/wheels on my new GenIII Prius IV (not to mention the cost of the sensors themselves...ouch). But, it sounds like the approach described here will do the sensors for me and also provide some cool data as a bonus.

Would you recommend that I just go with the dumb TPMS tool, or is this or some other option available that will prove useful more than twice a year?

Thanks!

Bill

P.S. I'm new to Prius, but have been eying them for years. I'm truly thrilled with the car, but it really irks me that Toyota doesn't provide a user friendly way to perform mundain tasks like changing tires, or backup beeps! [rant off]

 

Thanks for the response, Rachael! I agree that the financial investment makes sense. I'm more concerned that it will be too complicated for me to get it working. I have experimented with some "undocumented" stuff on computers, calculators, electronics, etc. And, I've wiped out memory a many times as I learned what works. I'm a bit nervous that I could hose up my new car

Thanks again!

Bill

 

Other than changing some settings what does Techstream buy us? Is there any routine maintenance that would require Techstream? I know that bleeding the brakes does.

 

I think it would be nice if we all pitch in a little bit and take turns to use it or ask PC to by one and let us rent it out. I only want it to activate my alarm and get rid of the seat belt warning.

 

I personally don't understand why there is no second source - I think the interface is fairly generic...

 

I wonder too!! I am living in Texas and we don't need to switch out the tires , so it is pretty much an one time thing for me other than turning the error code off. But turning the code off doesn't worth spending $500 on it. I asked my dealer and they are scared to take off the seat belt warning for me. And when I asked the other dealership to activate my alarm for me and they are trying to charge me the whole 2 hrs of labor for 5 mins of work.

 

I don't know that I would call it "generic" - but it is at least somewhat standard, as it is a J2534 interface with enabled programming voltages/pins. Even the software drivers themselves use standard commands complying with the J2534 spec.

I believe what is unique and manufacturer/vehicle specific is the data that is sent via those J2534 commands - and that is where Techstream is required. Any secondary software tool would need to "reverse engineer" the Toyota-specific data, which changes somewhat with versions of Techstream, as well as versions of the ECUs and programming (calibration) files, which Toyota updates on a regular basis.

Programming ECU's is significantly more complex (and unfortunately proprietary) than reporting OBDII codes and reporting sensor data over that "standardized" interface.

 

I found something call ALLSCANNER Toyota Techstream, does anyone know what is that?