Building a LT1 $EE ADS file from ALDL DS file?

[EagleMark]

0xB4 and 0xB3 are the checksum.

Ahhh from the guy who has made the coolest xdf and adx!

Now since I am trying to add the other Mode 1 data fixed messages how does one calculate the checksum? I just saw a pattern of it going down... but it should be calculated from something?

I'd sure like to get the EE,adx working for the 94-95 LT1 engines. It connects and gets some data, some wrong data and some NO data...

[historystamp]

I'd sure like to get the EE,adx working for the 94-95 LT1 engines. It connects and gets some data, some wrong data and some NO data...

I assume you know ...

'94 & '95 were the transition years from OBDI and OBDII. Some people refer to it as OBD 1.5. This could be why you are seeing so many data streams.

Checksum is a value calculated from the data that is pasted onto the end of a data stream by the sender. The receiver recalculates the value to compare to the sent checksum. This way the receiver can tell if the data was sent correctly or was corrupted on the wire.

I read calculating the checksum as you sum up all the data. Discard any bits that flow out of the 8 bit value then flip the bit values: 0 to 1 & 1 to 0. ( Called one's compliment. )
0xF4 + 0x56 + 0x01 = 0x14B chopping = 0x4B complimenting = 0xB4
Same result as Luke Skaff's pdf page 21
I'm not sure were the idea of the 0xFF entered the picture. Seems to be a red herring.

Robert

[EagleMark]

I think your on the right track, I can't imagine that all of those different modes would be needed. In $0D there are other modes that are not used and even complete data streams that could be accessed, there is a lot of repetition.

My advise would be to look through the $EE hack for the useful data streams, and focus on those only. The same info that is in the ALDL file should be in the hack as well. Of course this depends upon having a well commented $EE hack.

I have sorted them and discarded repeats and discarded the OBDII stuff as you suggested. Then when I looked in the only available EE.adx I could see where some were duplicated, probably causing some of the issues.

One duplicate is error codes, one is New MALF, one is MALF and one is stored MALF... so I am getting it down to one...

The only $EE hack I have is not much help when trying to compare to ds or adx although it is easy to follow the hack to XDF (mask) So if anyone knows where I can get a better commented one it may help!

I think the hack from ALDL.ds is the ads, but that is what I am trying to learn to do. If the ads was available for A239 A273 A274 A275 A276 then I would not have to learn how to. It seems they are ones never done on TP website.
http://www.tunerpro.net/gmOBDI.htm

I assume you know ...

'94 & '95 were the transition years from OBDI and OBDII. Some people refer to it as OBD 1.5. This could be why you are seeing so many data streams.

Robert

Yes I knew that, and looking through these ALDL files some have both OBDI and OBDII MALF flages, some don't. Figures I would try and learn on the hardest. With all the hours into this I can look back on 160 Baud which is simple and 8192 baud for earlier years then the 94-95 and understand it now!

I do appreciate your guys help! I am getting closer to understanding this and closer to getting one working!