Read Entire

[JoshMcMadMac]

When I perform "read entire" what exactly happens? I am curious if it basically "clones" the ECM, especially since it takes so long. I have pulled a file from one vehicle, and am wondering if the parts of the file that are not accessible/alterable through HPTuners are also copied over if I flash it to another vehicle.

[Chris@HPTuners]

it depends on the controller. generally, we read as much as possible and write enough to get the job done quickly. On the newer PCM's a write entire writes the OS & cal. On the older ones a write entire would effectively clone the PCM as you say (OS + Cal and other stuff).

Generally we moved away from that becuase the newer controllers cannot be "fried" as there is a boot section that is never erased (well it can be but we don't do it).

[JoshMcMadMac]

it depends on the controller. generally, we read as much as possible and write enough to get the job done quickly. On the newer PCM's a write entire writes the OS & cal. On the older ones a write entire would effectively clone the PCM as you say (OS + Cal and other stuff).

Generally we moved away from that becuase the newer controllers cannot be "fried" as there is a boot section that is never erased (well it can be but we don't do it).

Wow, thanks for the quick response, Chris!

So, if there is something different between PCM A and PCM B, but the difference is not something that is currently available for viewing/changing through HPTuners, is it safe to assume that the change is still copied over?

[Chris@HPTuners]

Wow, thanks for the quick response, Chris!

So, if there is something different between PCM A and PCM B, but the difference is not something that is currently available for viewing/changing through HPTuners, is it safe to assume that the change is still copied over?

if you do a write entire and the difference is part of the OS or calibration then yes.

eg. your car was tuned using software that had an extra paramater or something that we don't have, you read that tune, then write it to another PCM. Everything changed with the other s/w is written to the new PCM, not just parameters visible in our editor.

It has to work this way becuase when you write to the PCM, the first step is to erase everything (this is how flash memory works), you can't just erase and rewrite the individual parameters that are changed.

[JoshMcMadMac]

if you do a write entire and the difference is part of the OS or calibration then yes.

eg. your car was tuned using software that had an extra paramater or something that we don't have, you read that tune, then write it to another PCM. Everything changed with the other s/w is written to the new PCM, not just parameters visible in our editor.

It has to work this way becuase when you write to the PCM, the first step is to erase everything (this is how flash memory works), you can't just erase and rewrite the individual parameters that are changed.

You make me happy.

Thanks, Chris. I assumed this was the case...but you know what they say. It is always better to hear it from the horse's mouth!