Hi guys. I was wondering what definition file are exactly. It doesn't really say in the tech arcticle, and I did a search, but appearently many posts include the words "what is a definition file".
I will be using an 8746 ecm and the $61 tunercat software (since winbin .ecu files aren't out there for this ecm). The primary change I need to make to my chip is the injector size (I'm running rich even at the lowest psi possible). Other changes that need to be changed are: speed limiter, auto to manual tranny, obvious air/fuel ratios and spark, and probably egr disable.
Could I do this without spending $20 for each definition file?

 

Sure, get a hex editor, a calculator, the various formulas, and commented hac.

$20 is a give away price for the effort involved, in doing a .TDF.

 

Do I need the definition files to get started? i.e. the changes I stated above? I'm new to this, and it all seems pretty intimidating.

 

You only need one definition file...the one for your ECM and software combination.

For example, I'm running a '730 ECM and 1991 F-Body software. Look it up on TunerCat's site, it says I need the "$8D" definition file. $20 bucks later I'm in business.

As Grumpy said, you could always dig around for a commented disassembly of your ECM's software and use a hex editor, but that's pretty deep water to be swimming in.

 

A "definition file" is a TunerCat term that has been adopted to refer to a particular TDF for the "ECM ID" inside each eprom.

For your car, the ECM ID is "61", so TunerCat developed a $61.TDF for your ECM. For 1990-1992 SD TPIs, we use the $8D.TDF. On MAF TPI cars there are a number for the 165 ECM alone, $32, $32B and $6E.

So, for TunerCat, you must get a TDF (the definition file) for your particular ECM ID (inside the eprom). As mentioned by the others, you only need one TDF for your particular ECM Unless you plan to use TunerCat to modify eproms of other ECMs with a differenct ECM ID. I.E. You want to start tuning $8D or $6E in addition to your $61.

 

From the tech article...
"ALL of these editors have special calibration files (also known as definition files) that you load into the program before opening your BIN. This calibration file tells the editor exactly how to read your BIN. The BIN needs to be interpreted appropriately and the 'calibration' file takes care of this. This is extremely important because not all EPROM images are organized in the same manner. A good example of this would be comparing a 1989 IROC-Z to a 1990 IROC-Z. The 1989 IROC-Z uses a Mass AirFlow Sensor (MAF) in order to directly measure the amount of air entering the engine in order to supply the appropriate amount of fuel. However, a 1990 IROC-Z, which uses Speed Density engine management, does not have a MAF and does not directly measure the amount of air entering the engine. Thus, you would expect that these cars would have different code in their EPROMs. Well, in fact, they do. Thus, the editor needs to know where to find the appropriate information inside of the BIN. This is accomplished by loading the calibration file into the editor before loading the BIN."

Tim

 

FYI, I've noticed a few differences in WinBins "ECU" files, and TunerCats "definition" files. Tunercat can change some values winbin can't, and visa virsa.

Eventually, I'll end up in a hex editor changing things, searching message boards for what memory address does what, etc. No DEF file is complete, its all guess work. So you'll want to get both editors, if you can.

Initially I, like everyone else thought it was a big expense. I put it off FOREVER. But after the 150.00 programmer, chips, misc parts for ALDL cables, etc, frustrations with one editor, you don't mind spending extra money..

-- Joe

 

You have two options:

1) Notify TunerCat of the particular Constant, Switch or Table you want them to add, and, if possible, why it would be useful for tuning. TunerCat has been very responsive to things I have pointed out to them and incorporated them into future releases of the TDF. A lot of the changes to the $8D and $6E has come from many of the requests from members of the DIY Prom Board.

2) Get the TDF Editor and add them yourself. It really isn't that difficult to use and then I can add anything I want and not have to wait for TunerCat to provide them. In fact, on occasion, I have given copies of TDFs that I modified to TunerCat to offer to other TunerCat users.

3) Wait long enough and TunerCat will most likely add it.

Buut remember there are lot of tables defined that normally SHOULDN'T be touched unless you have a clear idea of how they work. If you want to "fiddle" with certain tables "just to see what happens", remember it maybe cheaper and easier to use a "Test Bench" rather than your own car.

 

Hi Glen,

Most likely. I'll prolly buy the TDF editor this weekend. I really am gonna need some more documentation on all the address ranges of the $6E. Supose I should do lots of searching tonight.

Still trying to find a useful Zif. Perhaps I can borrow one from a old peice of hardware in my basement.

-- Joe