You want to know why strange things happen only sometimes? I'm not really sure if I should answer that question or not. I'll need to dig deep into what the competitors are doing and eventually doing wrong. Anyway, comparative advertising is legal. Just let's not start another "transmission war". Ice cold technical facts and that's it. OK?
The answer to that question will require quiet some typing. Sit down, relax, read... .
To begin with more technical background is needed.
Let's start from the different software revisions that Chrysler has released and is still releasing. Let's take my test mule as an example. It's an 2006 / Automatic transmission / Federal emissions. The latest and greatest matching software for that truck is : 35 325 55 3 AR. Where "35" = 2006 ; "325" Hp ; "553" the transmission type; "AR" describes the software revision. They started from revision AA and today the latest revision is AR. That means they went AA, AB, AC, AD, AE and so on. Several...
Important for the analysis of the problem we're talking about is that the LENGTH of the softwares have varied through the different revisions. Sometimes but NOT always DC needs to add new parameters to the existing software. They need to insert some bytes here and there in the software. The new software revision is longer than the previous one and consequently the bytes in the software are shifted.
OK?
Now let's see how that relates to the "trip data". ( For simpleness I call them trip data but in reality much more is involved. Key counts, trip data, secret key, VIN#, trip data & & & )
Basically today there are three different approaches for the trip data.
1) Smarty reads them from the ECM, shifts them into the correct location in the software that he's going to download into the ECM.
2) Erase them like the DRB or StarScan would do. ( Dealer) That's what Bullydog did for quiet some time. We all know that the dealers have learned to watch out for the missing trip data and certain codes. (Most other downloaders still do it this way. )
3)Bullydogs "new" way. Since the trip data are all within about 4K bytes at the END of the software, they've come up with a new idea. They don't erase them nor do they overwrite them. Smart move, the trip data remain exactly like they were before they updated the ECM.
Really?
Let's see... . Things become a little tricky now. To make the understanding of what happens easier I'll use a couple examples.
First example.
Let's say my truck has revision "AQ" in it and also the Bullydog has revision "AQ" on board and writes that one into my ECM. The locations ( technically addresses ) where the trip data were before the update are the same as after the update. Perfect! The Trip data are saved, everything works like it's supposed to.
Second example.
This time my truck has SW revision "AR" on board and the Bullydog is still the same as before. It has still revision "AQ" on board. Now it happens that revision "AR" is LONGER than Bullydog's revision "AQ". You connect your bullydog to the truck and it WILL download SW revision "AQ" into your "AR" ECM. Same as in the previous example, bullydog does not erase / overwrite the trip data. I don't think it needs any further explanation that all the trip data are now located at the wrong address. PROBLEM!!!
To keep it as simple as possible. When the ECM is asked "Read the key count" it'll look into the location where SW revision "AQ" knows to find them but it finds the "AR" stuff (which is longer than the "AQ"). Sure the ECM will read what it finds in the requested location but WHAT it finds there is ???? The trip data are screwed! I've seen an average mileage in the ECM of 54517 miles per gallon, final timing 46895 degrees, after the bullydog... Go figure!
NEVER write an older software revision into an ECM that already contains a newer one. Besides the fact that the customer will loose it's latest update, not only can it screw the trip data. Depending upon what revisions are involved it can even kill the ECM... .
Now you take Smarty and update that ECM with him. It reads what's supposed to be the trip data, shifts them into the locations for the "AR" software revison he has on board. Voilà, Smarty writes screwed data into the ECM.
There are only two ways to get rid of the screwed trip data.
1) A reflash by a dealer. DC's tools do not save any data from the ECM before they download new SW's thus they will erase the screwed trip data. (Keep in mind, If a dealer checks the trip data he will see senseless things... )
2) I can do a special software for Smarty that will erase the trip data and update the ECM with a stock SW similar to what the DRB / StarScan would do. Done that several times by now to get rid of the Argentina/ Brazil SW that our competitors have used / are still using. A dealer can not flash those SW's back to a Federal / CARB one even if they wanted to.
And that's the end of the answer.
Marco