When we're reflashing a factory fitted ECU, one of the very first tasks that
we need to complete is to download the stock calibration or ROM file
out of that ECU and save it.
This means that later on, if we're not happy with the way our tune is progressing,
we've always got that base ROM file to revert to.
In this free lesson, you'll see how this task is completed.
The very first step of our six step process is to download the existing ROM file
or calibration out of our ECU.
This allows us to save that in a safe place, this gives us a ROM file that we can always
revert to at a later point if anything goes wrong and we don't like the direction
we're going with the calibration we're working on, we can also use this
stock ROM file as a comparison file, making it really easy to see exaclty what
changes we've made and we can then use that compare file just to revert selected
tables or parameters back to the values that they were in that stock calibration.
Before we can download the calibration or ROM file out of our ECU, we need to start
by installing the VCM suite software on our laptop.
Now it's always a good idea to make sure that you're working with the latest version.
This is updated reasonably regularly and making sure you stay on top of these
updates is important to make sure that you've got access to all of the latest
parameters in the scanner as well as additional functions such as speed
density calculation for the Ford ECU which was added relatively recently
before we filmed this worked example.
Once you've got the software installed on your laptop you can then connect
the HP Tuners interface between your laptop and the OBD2 diagnostic port
on your vehicle.
Next we can key on the vehicle and we can then perform a read.
In order to do this, all we want to do is click on the little read icon that we can
see on our toolbar here.
This will then open up the vehicle reader box which you can see and we can click read.
Now this process can take several minutes.
It's important while you're doing this to make sure that your laptop is powered,
and it's also important to make sure that the battery in the vehicle is in good
condition or alternatively you can connect a booster pack to the battery during
the reading and also the writing process.
Let's go ahead and wait for that read to complete now.
Once the ROM file has been successfully read out of the ECU, we've now got the
opportunity to save it.
And what we want to do here is give this file a sensible name so that we're
going to be able to easily locate this later.
This becomes much more important once we've tuned several hundred
vehicles, potentially we've got a lot of files stored on our laptop.
Now it doesn't really matter what naming strategy you come up with.
Personally I use the registration plate of the vehicle along with a description
of the vehicle and finally a description of the calibration.
And this is a convention that I try and stick with and I suggest that you do the same.
Regardless how you name your files, just make sure that you're consistent.
So what we're going to do here is give this a name of the registration,
then I've added Ford F150 SC for supercharger and then base tune.
I'm going to save that now.
Now if you haven't already licensed the file which is quite likely the first time you
read from the ECU, you'll also have the opportunity to then license the file.
And this will allow you to apply some credits to that file, unlocking the ECU
and allowing you to actually perform any tuning work.
It's also a good idea at this time just to make sure that you're not going
to end up accidentally overriding that file once you've made changes,
to also use the save as function and give the file a different name.
In this case we'll use the term tuned at the end of it.
So let's go and do that now, we'll go to our file menu and we'll click save as.
And all we're going to do here is just change base tune to tuned,
you could quite likely also use a term such as final tune.
So this will now mean that we are working on that tuned file,
so any changes won't affect the base calibration or base ROM that we've
just downloaded.
Alright with this step out of the way, we can move on with our process.
That was just one module taken from our complete practical reflash tuning course.
This course is perfect for anyone who wants to learn the techniques of reflashing
factory ECUs.
In particular you'll learn about MAF based versus speed density based ECUs and you'll
learn advanced techniques such as how to correctly recalibrate your mass air
flow sensor, how to adjust your calibration to suit a larger set of injectors,
how to perform a speed density patch to remove the factory mass air flow sensor,
and how to use a scanner or datalogger package to optimise your tune quickly
and efficiently.
If you want to learn more about this course, click the link in the description.