No reset ECU button? It's supposed to be there. If it isn't, let Duram know. Yes, you need to reset the computer, not just the time, the whole thing. You need to reboot so to speak, otherwise you just wrote it into memory but it didn't load. I guess another way you could try is to select the value you want, exit, then unplug the car battery, unless the ECU has it's own battery, then you're screwed. Anyways, let BT do the work, they say this change between the 4 values should work, and I believe them. When I first tried there was no coding at all, a few days later, whala...
To me, ROM and non-volatile memory are the same thing, so can you clarify. ROM is read only memory, a type of non-volatile memory, more specifically that which doesn't disappear when you remove power.
How does it determine run time. For example, if I set the clock on my car back to when the car was produced, does it take effect, or if I set it to 13 yrs. later??? There is such a thing as speeding up the clock for another example, reminds me of overclocking a computer, just increase voltage, if you dare...
Coding at what level. There are a few levels to consider, there is the one given to the interface user, like windows when you boot it up, that is controlled by the manufacturer. There is also coding underneath at the assembly language level, or at what is called machine language. If you can get to the machine language and change it, you can do anything, (this being the 1s and 0s that the computer reads.) Since you already gave me two conditions where recoding can occur, early and late in life so to speak, I know that it can be changed, just have to figure out how.
Bottom line, if you can figure out where the value TRT is stored, and manipulate it, you can do anything right?
Quote:
Originally Posted by DMETune
Jim and I conducted a few tests tonight and have been unable to change the Vmax (speed limiter) at all using the BT software and Pro cable.
I'll lay out the testing method here. Perhaps your results will be different, or perhaps not?
It was established earlier that the VMax cannot be removed by recoding the DME, but rather, can be changed to one of four pre-programmed values. It's important to note that DME Tune, Dinan, and others 'delimit' vehicles in the ROM rather than within the non-volitile memory that is targeted with recoding. Within the DME code, there is a restriction that states that any recoding must be done within the first ~53 minutes of total run time (TRT), or after about 13 years of operation (no joke). This stipulation begs the following questions:
1.) Is the BT software somehow resetting TRT and therefore allowing recoding? This would impact fault codes as they, among other systems, rely on TRT to track when faults occurred. Resetting TRT would also likely set off warning bells to a service advisor who encountered a 2007 vehicle with 30k miles and only 6 hours of TRT. 
2.) Is there a bug in the DME software that doesn't enforce the TRT restriction? Unlikely, but not impossible.
We decided to find out using a simple test that you can perform if you have the Pro cable.
First, we needed to find out my TRT value. We did this by using the Command Console and entering "21,C3" (without quotes). The returned value was "61,C3,01,6B,0E,59" which translates to 660 hours.
Next, we obtained my exising "speed limiter index" value by entering "22,30,10" into the Command Console. The result was "62,30,10,01."
So using the BT recode tool, I changed my speed limiter to the lowest value in the dropdown list, 206, and rechecked my speed limiter index using "22,30,10" again. It was unchanged, "62,30,10,01."
You're probably thinking to yourself that I need to reset something, right? Well, we then went into the Commands area and reset the "Run Time" selection because, after all, the pesky TRT value is what's stopping us from recoding, right? Another check of the TRT value using "21,C3" returned the pre-existing 660 hours, and the speed limiter index remained unchanged as well.
Thoughts welcome. |