Well I tried to post a bin. file but it won't let me. I bought a custom wiring harness, 7730 ECM, and Memcal with prom, for the SD TPI in my jeep and when I open the file in Tunercat I get this message. "Source file has been modified and checksum disabled, proceed anyway?" It is working fine I just wanted to find out what Bin. is on it and what has been modified. I can open it and modify it just fine I just get that message when I open it. Any way to post the Bin. for someone to look at?

 

email it to me ill se if i can properly id it. worse yet it might not be all gm code uugghh.

 

No, you cannot post a BIN (or any other file) as an attachment other than a "picture file" like a JPG.

I suspect you are getting the message because prom in the BIN does not have "8D" in byte 8 of the bin (location 8008). Most likely it has the test mask "AA". "AA" in the 8th byte identifies a "test bin" ID often used by developers so you can't read the BIN with an Editor (such as TunerCat).

As I recall, TunerCat awhile back modified their Bin Editor to work on "test masks" like "AA". Before, if you had a BIN with the "test mask - AA" set on byte 8 instead of (say) 8D, TunerCat would not work on the bin - even if the BIN was an 8D bin and the only difference is "AA" as the test mask.

As for determining ALL that has been changed, you can get a Binary Compare program from TunerCat for 30 days and compare your BIN to a stock bin.

To check location 8008, if you have the Pocket Programmer, just load the Buffer with your BIN and then hit "Edit". Count to the 8th BIN (remember the first Byte in the buffer is location 8000, not 8001).

 

It does have AA in place of 8D. I have no problems changing anything on it in Tunercat. I just couldn't figure out why it would be set that way since the Prom was ordered and they knew nothing about my setup so I wouldn't think it would be a custom Prom.

 

Using AA, disables the Checksun routine.
The problem is that it allows for bad prom to run the car, thou something might be wrong.

If the 8D editor works, I'd suggest you reset the 0008 location back to 8D. I'd rather have a CE light then run with the chip being wrong.

 

its $8d. im not sure how modified it is but it looks as if only the data areas have been changed. grumpy is right however you should change the 8th byte back to $8d.

 

Most of those "AA" eproms I've seen by various prom burners tend to only change the tables. I've even seen a couple modify the actual "Program ID" to something unique so you had to actually look at the 8th byte and then the code - only to find it was STILL basically a stock eprom with minor tweaks.

If you truly want to know the differences, I'd use TunerCat's "Binary Compare" program. It's free for 30 days as I recall. But I found it quite useful and actually bought it.

 

I did some comparing to AUJP1615 which had the least amount of differences and this is what I came up with. Can you tell by the location what is changed?

-------------- AUJP1615-----------My Bin.
000007---------39------------------02
000008---------8D----------------- AA
000016---------10------------------00
00024A---------CE------------------C6
000377---------C1----------------- A3
000378---------C5------------------A7

 

0007: checksum
0008: ECM ID
0016: VATS disabled
024A: Turn off EGR diagnostics
0377: Fan 1 Turn off Temp (changed to 82*C)
0378: Fon 1 Turn on Temp (changed to 85*C)

I hope you didn't pay much for this "custom eprom". It basically a stock bin and does nothing other turn off a few diagnostic errors and lowers the fan temp. You can change those parameters in a couple of minutes.

Also, turning off the EGR diagnostics does not disable the function of the EGR in the code. All it does, is suppress the reporting of an EGR error code. They should have disable the EGR by increasing the EGR enable temp to a very high value like.

Overall, any beginner could do better than this eprom. It has done nothing for performance.

 

It was just in the ecm when I purchased the wiring harness and computer. It was not supposed to be a custom prom so that is why I wondered what was different about it. Thanks for the input though. So if change the AA back to 8D I will quit getting the error when I open it in Tunercat?

 

Yes. In fact, when you re-open the bin with TunerCat, it will automatically recalculate the Check Sum.

Alternatively, you could start with a "virgin" AUJP bin and just make the changes you want, and then reburn it. It appears that the Memcal you got is nothing special, so why not just start with a known good version of the AUJP?