Practical Reflash Tuning: Step 1: Downloading Base ROM
Watch This Course
$229 USD
-OR-
Or
8 easy payments of only $28.63
Instant access. Easy checkout. No fees.
Learn more
Step 1: Downloading Base ROM
14.17
| 00:00 | - So before we download the stock ROM file, we're going to need to get the HP Tuners software off their website. |
| 00:07 | To do so, we go to hptuners.com, click the downloads section and you'll actually be presented with multiple options so HP Tuners has a VCM Suite latest stable version and then a beta version. |
| 00:23 | While beta isn't necessarily the way you want to go with some other platforms, I find that HP Tuners beta is the way to go, it is actually stable, it gives you the latest vehicle coverage and feature support, so we're going to go ahead with the beta download. |
| 00:38 | We do get another beta warning and if you do happen to run into anything that seems quirky, you can always go back to the stable version. |
| 00:47 | While that's going, at this point you can get your HP Tuners dongle and cable plugged into the OBD2 port on the vehicle, get the USB cable plugged into your laptop and then you'll be ready to go when the software finishes downloading. |
| 01:01 | If you've already downloaded the software, you can always make sure that it's up to date by going in the help menu to the about section and attempting to see if there's an update available. |
| 01:13 | So it looks like my software was already up to date and in that case, we'll just go ahead and open it. |
| 01:19 | Again we get another warning, this is beta software, again not to worry. |
| 01:23 | So we'll click through that. |
| 01:27 | Next let's get ready to read our stock ROM file. |
| 01:30 | In order to do so we're going to use this button here for read vehicle. |
| 01:35 | But first we need to make sure we have the vehicle powered up correctly. |
| 01:39 | Now if you have a key start vehicle you're going to go two clicks to the full on position but without cranking to start the motor and if you have a push start vehicle like the one we have today, you're going to push the push button, turn the vehicle on without touching the brake pedal, or if you're in a manual transmission vehicle, without touching the clutch pedal, to avoid the engine starting. |
| 02:03 | Now depending on the vehicle you may have to push the push button once or twice to get the vehicle fully on. |
| 02:11 | Now if your vehicle powers up to an accessory mode, which isn't fully on, the ECU likely will not have power at that point so in this car again, one click, but yours may require two. |
| 02:27 | So we've got the vehicle on. |
| 02:31 | At this point it's good to make sure that your battery has a good charge. |
| 02:34 | If it does not, you may need a tender and in this case we actually are using a battery tender. |
| 02:39 | So right now we have it on a 15A charge, depending on the state of your battery you may need more or less, hopefully not more. |
| 02:49 | If you need more, it might just be time to change the battery out. |
| 02:52 | It's really important to have the voltage in a proper range while performing any critical read or write operation on the vehicle to avoid interruption. |
| 03:01 | So let's go ahead and right before we read, I'm going to gather info. |
| 03:07 | Now the reason I'm doing this is at this point it gives you the opportunity to confirm the vehicle is what you're expecting, in terms of the PCM that's in the car. |
| 03:18 | So we're showing 19 Cadillac CTS-V 6.2 litre 8 cylinder. |
| 03:24 | That's what we want to see in here, had we seen something else, we might now become aware that this has some sort of swap, or someone's been in here and potentially loaded an incorrect ROM onto our vehicle. |
| 03:38 | So no surprises which is great. |
| 03:40 | The other thing we can see here is the other modules that we might potentially be able to talk to like this second one here, the TCM which is the transmission control module. |
| 03:51 | In this case, we won't be tuning the transmission so in order to save time, I'm going to click do not read on the additional modules and that way we'll only get the ECM, engine control module downloaded. |
| 04:04 | Let's go ahead and read it. |
| 04:09 | And this will take a few moments. |
| 04:13 | So we'll let that download and then once it's downloaded, we know what the PCM matches what we're expecting, what we don't know for sure in some cases is whether the file we're downloading is actually stock or not. |
| 04:27 | So once we get it downloaded, what I always like to do is compare to a known stock file and just see if any changes have been made. |
| 04:35 | That way, we don't start with a file we think is stock but really has some unintended changes which could catch us out later. |
| 04:42 | There's a couple of ways that you can get a stock file from HP Tuners. |
| 04:45 | One of them is to go back to the HP Tuners website and at this point we'll go into your account. |
| 04:52 | Accounts are free, if you haven't set one up, just set one up. |
| 04:57 | We'll go to the tune repository. |
| 05:01 | And here you can enter year, make, model, engine, transmission, click search and see if your vehicle shows up. |
| 05:10 | Now in this case, there wasn't a ROM file for this vehicle available through the tune repository but by emailing the support address at HP Tuners they were happy to provide that file to me. |
| 05:22 | So once we get the stock file downloaded off this car, we'll just run a compare and then see if we find any differences. |
| 05:30 | So now that our file has downloaded, we're going to save it and you can see here I already have that stock file from HP Tuners so I'm going to save this as was on ECU, hopefully stock. |
| 05:46 | And that's just a mechanism I like to use, was on ECU, that lets me know that this is whatever was on the vehicle when I got there, doesn't necessarily mean it's stock yet, we'll figure that out. |
| 05:57 | Now while I was able to save that file straight away, if you haven't already licensed the vehicle, at that point you'll be prompted with a message of how many credits this vehicle requires to license it and then you can verify the cost of those credits, depending on where you're purchasing them, and determine what the final cost will be. |
| 06:17 | At that point you have the choice of licensing and saving the file in a manner so that you can make changes and flash it back to the car, or not license the car yet, review what's on the car and then decide where you want to go from there. |
| 06:32 | In our case, the vehicle's already been licensed which means it has already been tuned but I believe that is a stock file on it now and let's just double check that that's the case. |
| 06:41 | So in order to do that, we're going to go to compare and open a compare file. |
| 06:48 | So I'm going to compare the file I downloaded to the file I got from HP Tuners, stock file from HPT. |
| 06:56 | So we've opened up for a compare and now we're going to go to view comparison log. |
| 07:03 | And as you can see here, there are no differences, nothing to be seen. |
| 07:08 | So we do in fact have a stock file on the vehicle which is great, that's a really good starting point, again if you're starting with something that's already modified, you don't necessarily know if the changes that have been made are something that's going to be ideal for your situation so best case, start from stock. |
| 07:25 | Now that we have the stock file downloaded, let's go ahead and take one extra step. |
| 07:30 | What I'm going to do here is I'm going to save this file as Modified1. |
| 07:39 | Now clearly I haven't changed anything yet, why am I doing this? I'm doing this because if I don't save it now, what I'll surely end up doing is hopping into one of these sections, making a quick change, clicking save out of habit so I don't lose my work and now I've altered my stock file right. |
| 07:59 | So if you catch yourself quickly enough you might be able to undo a few times, get back to stock, save that again, or you could always read the file off the ECU again and start over with a stock file. |
| 08:14 | But in order to save myself wasting that time, I'll just go ahead and immediately save a file with a new name to avoid corrupting or making unwanted changes to my stock file. |
| 08:26 | So that way I can always refer back to it and know where I started from and I also find that as I'm tuning a street vehicle like this, I really like to make sure I only make changes that are absolutely necessary and referring back to stock as I go is a great way to kind of ensure that I haven't gone off in the weeds and done things that maybe just aren't really necessarily needed or critical to the application. |
| 08:52 | So we've got the stock file saved, we've got our first modified file saved and this is a good point to pause and just start to look over what's in the stock file. |
| 09:04 | So as we start to look through this ROM, the GM Gen V is certainly more complex than in the past and you're going to see some things that you perhaps haven't seen before if you've been working on GM Gen 3 or Gen 4 vehicles. |
| 09:18 | But one of the things to keep in mind is while there are a myriad of new tables, some of them aren't necessarily having an impact on the calibration and I'm going to give you a few tips on how to weed through that and hopefully as we do so, it'll remove some anxiety with the volume of things available and help you realise that you don't necessarily need to worry about many of them and in most cases, you won't even need to touch most of these tables. |
| 09:48 | So let's just poke around and I'll give you a few examples. |
| 09:52 | So the first example is there's a system within the torque modelling and control system called torque shaping and in this case, it's disabled. |
| 10:02 | So if you see a pull down menu, with enable or disable and disable is selected, any and all items related to that system are not something you need to worry about because they're not active. |
| 10:16 | Another situation where you don't have to concern yourself necessarily with a table unless you want to take advantage of it, is something like this. |
| 10:27 | Now in this case, we're looking at the maximum torque table which is RPM vs gear and if you look down at the lower right hand corner of the window, you'll see that the range of values that can be populated in this table go from 0 to 6042 and in the table all of them are completely maxed out so what does this mean? This means that this table is present, however the value is so high that it's moved out of the way and will not have any impact on our tuning. |
| 11:04 | Now if you make this value smaller, you could use it as a torque limitation per gear or per engine RPM. |
| 11:11 | And in a traction limited situation, this might actually be of use but if you're just looking to make the most power possible, these values are already completely moved out of the way and will not inhibit your ability to make power. |
| 11:25 | Next let's look at this table here, we have the open loop IVT gain startup multiplier. |
| 11:31 | And that's a mouthful and it looks like the description here, it says that it's a multiplier for startup conditions, we don't really have a full picture of what this does but what we do know from looking at the table is it's a multiplier table which is fully populated with the number 1. |
| 11:49 | So of course if we multiply something by 1, we get no change which means that in stock form, this portion of the control strategy has no impact and if it's not needed from the factory and you haven't made massive changes to the vehicle, you likely won't need to manipulate it either so when you find something like that, it's a great opportunity for you to say look, this is one of this tonne of tables that's here, I don't really know what I need to do with some of these and now I know this is probably one that I can just simply ignore. |
| 12:21 | Next let's go to the power enrich section and I'll give you an example where there's a whole control strategy, in this case called the knock enrichment strategy, which is designated by the bold and underline heading and then the adjacent tables and 1D values is all related to knock enrichment. |
| 12:41 | So in this case, right now we see a few things that are listed as enable conditions and the reason I mention this is we see a enable coolant temperature of 493 and then the description at the bottom indicates the engine coolant temperature value must be exceeded to enable this mode. |
| 13:03 | So we surely will not be exceeding 493°F which means that this entire system in stock form is not active. |
| 13:12 | And again, if it's not active in stock form and you don't have a compelling reason to activate it in your application, just leave it off. |
| 13:20 | Next let's go to the spark section under the advanced tab and we see something called piston slap. |
| 13:28 | Now this is a control strategy which is listed as a base correction. |
| 13:32 | Any time we have a correction, it can be considered like an adder or an offset so this is something that would be added to the spark advance and what we see here is the entire table is filled with zeros which means nothing will be added to our spark advance. |
| 13:48 | Again this system will have no impact on our spark timing. |
| 13:53 | So again, there's quite a lot of things in this control strategy, we have tonnes of options, many of them however don't even do anything from the factory so before you get overwhelmed, just poke through and realise that many of these things are not something you need to worry about at all. |
| 14:13 | Now that we've downloaded and reviewed the stock ROM file, we're ready to move on to the next step. |
