HP Tuners Tutorials

[Gregski]

Originally Posted by DWilbur

Thanks for posting this info. I spent the last 2 days reading through this thread and I'm thinking about doing it my self. Just got my truck back a couple week ago from paint jail. I installed a 2004 5.3 after have it rebuilt NV4500 trans and Atlas T-case. Engine and wiring out of a 2004 Suburban.

Thank you for reading, and mad props on the manual trans build!

[Gregski]

HP Tuners Tutorials - Chapter 1 - Logging

figure might as well do a bit of a write up on the VCM Scanner, just to give the VCM Editor a little rest, ha ha

when you first fire up the Scanner and connect it to your vehicle it will load one of two pre existing channel configurations (you can see these choices in the upper left corner of the left pane when you click the yellow Open Channel Config icon below the yellow Open Log icon which looks similar)

1. SAE Defaults

~ OR ~

2. Vehicle Defaults

Either one will give you a cluttered screen yet not everything you need to tune what ever you want to tune, ie idle, cruise, WOT.

The screen is really divided into three panes which in the defaults look like this (you can later shuffle these all around):

1. on the very left is a Channels pane (#1)

2. on the top right is a pane that usually holds the Gauges (#2) and what used to be called a Histogram and is now referred to as the Graph (#3)

3. on the bottom right is a Chart vs Time (#4) what I call the EKG looking thing

So what I like to do is nuke and pave everything and start with a clean canvas and explain what it is we are adding and why, so won't you join me.

To get rid of the Gauges, Graph, and Charts just click the X in each of their individual windows and that will make them go away for now.

To get rid of all the Channels right click in the Channels list and select Remove All Channels.

If you want to follow along, you will not loose anything you are just changing the view.

[Gregski]

This may seem silly as we will be adding a bunch of Channels that we just removed, but we will comment on why we are adding each one and we will add them in a certain order (although yes we could have just reshuffled the ones we already had)

Arguably the most important sensor on our LS engine is the Coolant Temperature. I was raised thinking it was the Oil Pressure but the PCM don't even monitor the oil pressure on the Gen 3 trucks, so there you have it. A lot of Hot Rodders would vote for the Tach, but nope, the Tachometer slides down the list also.

1. So let's add this bad boy in, either right click in the blank Channels pane and select Add Channel from the little pop up menu, or click the gray gear with the green plus + sign next to it on the top menu.

2. This will bring up a Channel Selector, so let's type Engine Coolant Temp in order to narrow down our choices, we could hunt and peck for it using the drill down method, but I find typing in what you want is quicker.

3. Then double click the Channel you want.

Once added if you try to add the same Channel again it will appear highlighted in blue, simple.

[Gregski]

The PCM relies on the Engine Coolant Temperature to make decisions, we will go over a number of them later on, here we focus on a key decision and that is when to switch from something called Open Loop and start running is something called Closed Loop.

Simply put when we first start our cold engines, a lot of sensors are not ready yet, for example the O2 sensors have not warmed up to their operating temperature, so they can't start reliably reporting to the PCM what the exhaust gas conditions are. The PCM has no choice but to operate in it's best guess mode, so it relies on pre existing tables, in other words Excel looking charts or spreadsheets that say something like, hey man if the coolant temperature is 70* F try to idle at 675 RPM.

Then when the Engine Coolant Temp reaches 131* F (yours may vary) the ECT sends a signal to the PCM saying, we're ready for Closed Loop, and the system switches to Closed Loop and the PCM starts listening to the input (in other words relying on feedback) from the two narrow band O2 sensors among other sensors. More on this later.

The nice thing is that HP Tuners allows us to monitor the Channel that shows us loop status, so lets add it next:

1. So once again either right click in the blank Channels pane and select Add Channel from the little pop up menu, or click the gray gear with the green plus + sign next to it on the top menu.

2. This will bring up a Channel Selector, so let's type Fuel System #1 Status in order to narrow down our choices, we could hunt and peck for it using the drill down method, but I find typing in what you want is quicker.

3. Then double click the Channel you want.

And now we have two channels in our Channels pane, we will now be able to see how hot our engine is, and if we are in Closed Loop yet, baby steps.

[Gregski]

Essentially what we are doing is adding Channels that will show us the readiness of our sensors, so we are not just doing this for fun, there is an end goal in mind (aka Tuning later on, but only when all of our sensors check out).

One way to test our MAP (Manifold Absolute Pressure) sensor, that little guy that lives on top of our stock intake manifold in the back where we would expect to find a distributor back in the day, ha ha is to see what it thinks the Barometric pressure is without the truck even running.

You see the GM engineers are wicked smart, they knew these trucks were going to get shipped all over the place, and they had to run in San Francisco, ie sea level, Colorado ie mile high, and Death Valley ie below sea level, so they came up with a solution.

When you first turn on the key, the MAP sensors gets it's bearing and say's where the hewk am I, what is the starting pressure here that i will compute all the other values off of.

This is why I wait a second before I start my rig, now i know this happens in a blink of a gnats eye, but I like to turn off the radio (provided you have one), turn off the AC (likewise provided you have one), and listen to that fuel pump prime, then and only then do I fire it up.

1. So once again either right click in the blank Channels pane and select Add Channel from the little pop up menu, or click the gray gear with the green plus + sign next to it on the top menu.

2. This will bring up a Channel Selector, so let's type Barometric Pressure in order to narrow down our choices, we could hunt and peck for it using the drill down method, but I find typing in what you want is quicker.

3. Then double click the Channel you want.

Note: Sometimes you will see multiple similar selections, some may say (SAE) after the name some may not. Honestly just try one to see if you get data, if it's not working try the other. I could go deeper into this, supposedly the non generic SAE ones have "higher resolution" but all I know is sometimes one just works and the other won't.

[Gregski]

Now I am kinda anal, so I like to put empty spaces between non related channels in that list and group them together the way it makes sense to me, so you can right click on any item in the list and select Move Down to obviously slide it down a line and give us some breathing room.

It may not look like much when you only have three channels but wait till that screen is full, it will surely help.

[Gregski]

hey man loving the Tutorial but you lost me on Barometric Pressure bro

hold on a second, no one expects us to go all Neil deGrasse Tyson here, all we are going to do is look for two things with that Channel:

1. Check does it simply have a value, in other words is it even working? is it plugged in? if it shows all zeros we may have a problem, that type of thing

2. Check does its reading match the one on our iPhone in the Weather app, see where it says Pressure? That's the pressure in your area, that should match.

and keep in mind you're not going to check this every single time you fire up your truck, no, this is just once in a while when you want to troubleshoot an issue, or tune something on your rig, it's just good practice to ensure your MAP sensor is working properly that's all

[Gregski]

the MAP sensor can also show us Manifold Vacuum. In the old days vacuum was considered the nervous system of the engine, it provided feedback or controlled things, now it's all done with sensors and electronics, we may think of vacuum in terms of pressure now or negative pressure, what every they want to call it, but I like to call my vacuum, [ahem] vacuum, ha ha

1. So once again either right click in the blank Channels pane and select Add Channel from the little pop up menu, or click the gray gear with the green plus + sign next to it on the top menu.

2. This will bring up a Channel Selector, so let's type Vacuum in order to narrow down our choices, we could hunt and peck for it using the drill down method, but I find typing in what you want is quicker.

3. Then double click the Channel you want.

Note: We only typed "vacuum" yet it still found Manifold Vacuum. Cool stuff!

[Gregski]

the last two channels we leave grouped together cause they are related, since they use the same sensor, but you do you

[Gregski]

similar to the MAP sensor we want to check the Intake Air Temp sensor next, the IAT

the stock vehicle had something called an Ambient Air Temp sensor which I think was strapped to the grill of the donor truck, unfortunately that does not make it to our LS Swapped engine wiring harness so we will rely on the Intake Air Temp instead, it's arguably a better source of signal anyway as it sits closer to the engine.

On the 3rd Gen LS engines (4.8, 5.3, and 6.0L) the IAT lives in the same housing as the MAF. It is not a separate sensor, so when you move the MAF you also relocate the IAT.

1. So once again either right click in the blank Channels pane and select Add Channel from the little pop up menu, or click the gray gear with the green plus + sign next to it on the top menu.

2. This will bring up a Channel Selector, so let's type Intake Air Temp in order to narrow down our choices, we could hunt and peck for it using the drill down method, but I find typing in what you want is quicker.

3. Then double click the Channel you want.

Again all we are going to do is just see what the IAT reads before we even start the truck, to see if it matches our Weather app on our iPhone, it should.

[Gregski]

added a space before it and a space after it, and we are ready for the next Channel

Now, you should be getting a hang of this, and you don't have to add these Channels one at a time, we are just doing it for repetition and so that we can discuss and explain each one

[Gregski]

another important Channel to add is the Mass Airflow Sensor, not to be confused with the Mass Airflow channel which we will cover later. And shouldn't it be called a MAS and not a MAF (sorry couldn't help myself).

We want the Mass Airflow Sensor to show either 0 volts or 0 hertz depending on the units we have chosen, with just the key On, and the engine not running. Simple as that, does it show any numbers at all? Yes / No? If yes does it read zero. These are not bullet proof tests but they are designed to catch glaring errors and omissions.

Again just another readiness check.

[Gregski]

alright now let's add the Tach, the Tachometer or as these guys like to call it Engine RPM

We will beat this horse to death whilst covering Idle Tuning but for now let's just add it and make sure it reads something rather than nothing while the engine is running. You may be able to sense something is wrong and find that you skipped Part II - Change the Tachometer RPM output to an 8 cylinder V8. under the very first Series - Housekeeping of this tutorial.

I highly recommend nice big analog tachometers that show you a nice needle sweep up and down, the downword sweep being important to catch what we call a hanging idle.

I learned my lesson the hardway that digital Tachometers suck, they usually do not show/change the two right most digits those always show 00 so you can see 500 or 600 RPM but never 525 or 650 type of thing

1. So once again either right click in the blank Channels pane and select Add Channel from the little pop up menu, or click the gray gear with the green plus + sign next to it on the top menu.

2. This will bring up a Channel Selector, so let's type Engine RPM in order to narrow down our choices, we could hunt and peck for it using the drill down method, but I find typing in what you want is quicker.

3. Then double click the Channel you want.

[Gregski]

Though we will cover the many different timing advance channels later on, it doesn't hurt to add the main one for now.

1. So once again either right click in the blank Channels pane and select Add Channel from the little pop up menu, or click the gray gear with the green plus + sign next to it on the top menu.

2. This will bring up a Channel Selector, so let's type Timing Advance in order to narrow down our choices, we could hunt and peck for it using the drill down method, but I find typing in what you want is quicker.

3. Then double click the Channel you want.

[Gregski]

moving right along, we add the two O2 sensors voltage channels, again these are just for us to check if they are working properly, and operating between 0.100 to 0.900 volts

You see most sensors operate between 0 and 5 volts, the smart Wideband O2 sensors work that way, but our factory O2 sensors are dumb, they are simple, they only operate between 0 and 1 volt, so we shall check and see if indeed they are showing us readings between 0 and 1 volt (100 mV up to 900 mV technically)

1. So once again either right click in the blank Channels pane and select Add Channel from the little pop up menu, or click the gray gear with the green plus + sign next to it on the top menu.

2. This will bring up a Channel Selector, so let's type O2 Voltage in order to narrow down our choices, we could hunt and peck for it using the drill down method, but I find typing in what you want is quicker.

3. Then double click the O2 Voltage B1S1 (Bank 1 Sensor 1) and B2S1 (Bank 2 Sensor 1) Channels you want. Remember how we learned Bank = Cylinder Head earlier.

[Gregski]

moving right along and adding to our list...

[Gregski]

and rounding out our Channels list is Control Module Voltage, this is to ensure the brain is getting enough juice sorta speak

1. So once again either right click in the blank Channels pane and select Add Channel from the little pop up menu, or click the gray gear with the green plus + sign next to it on the top menu.

2. This will bring up a Channel Selector, so let's type Control Module Voltage in order to narrow down our choices, we could hunt and peck for it using the drill down method, but I find typing in what you want is quicker.

3. Then double click the Channel you want.

[Gregski]

Alright, there, isn't that better? having a list of only a handful of channels, ones we know exactly what they do, instead of a huge list of default channels that may or may not report any data because we did an LS Swap and some may not even have any sensors behind them.

All that remains to do now is to save our channels configuration, I like to save it as something called "Basic" because the system will add the word Channels to it so you end up with something like Basic.Channels.xml

[Gregski]

DISCLAIMER - Yes there are a lot of Channels missing from this list, but many of them pull their information using one of the sensors our channels are monitoring.

Also, for example when we go to Calibrate our MAF Sensor or VE Table, we will either add more channels to this list or build a whole new Channels list

[Gregski]

OK, let's use our Basic Channel config to evaluate the three vehicle conditions:

1. Key on - vehicle not running

2. Vehicle Running - Open Loop

3. Vehicle Running - Closed Loop

To do this we will hook up our Laptops to the vehicle and for the first one with the Key on press the big Red Button in our VCM Scanner and start scanning for a minute or two. Scanning just means recording the session. Then press the button next to it to stop the scan and save the log. (Saving the log is optional for these sensor readiness checks, but for now it's good practice.)

Then repeat the process for #2 above by starting the vehicle and then pressing the Start Scanning button, etc. Again record for about a minute or two and stop scanning and save the log. (Saving the log is optional for these sensor readiness checks, but for now it's good practice.)

After warming up the engine, do it again for #3 above, start the truck, record for a minute or two and stop the scan and save it. (Saving the log is optional for these sensor readiness checks, but for now it's good practice.)

[Gregski]

Key On - Vehicle Not Running - Systems Check

So first we look at the Engine Coolant Temp ok it's 57* F, so here are our thoughts:

• the Channel is working / the Sensor is working
  
• later we will know what should be happening at this temp, for now this is an unkown to us, but that's ok we are learning one bit at a time

looking below this Channel, at the next one Fuel System #1 Status says OL - Not Ready, our thoughts:

• We got some sort of result in here, so at least the channel is working, that's good
  
• OL must stand for Open Loop, ok we guess it's not in Closed Loop yet, we'll see what happens to this value later as the vehicle warms up and the temperature increases

[Gregski]

Key On - Vehicle Not Running - Systems Check

looking at our next Channel, Barometric Pressure, our thought are

• we have a value so we picked the right PID (Parameter ID) and the sensor is working
  
• comparing the value to our iPhone Weather app, they match so it's working properly

for now, the channel below Manifold Vacuum we just want to make sure it has a value, and it is as close to zero as possible

[Gregski]

Key On - Vehicle Not Running - Systems Check

now you may notice that the Barometric Pressure Channel reports in PSI instead of inHg (Inches of Mercury) hey that's Physics for you (seven different ways to say the same thing), and yes this is one of the things that you will do battle with in HP Tuners quite often, making sure you are comparing Apples to Apples and not Apples to Oranges type of thing, so simply right click that Channel select Units and choose the format you desire

[Gregski]

Key On - Vehicle Not Running - Systems Check

the Intake Air Temp channel is next, and this one can get skewed like in my case cause my truck has been parked in the shade all day so it shows a temp a few degrees below my iPhone Weather app

So you knowing this, maybe use a local indoor outdoor thermometer barometer temp gauge thingie to get a better reading of the local air temp, or park your truck in a different spot, you get the idea

[Gregski]

Key On - Vehicle Not Running - Systems Check

Mass Airflow Sensor shows a perfect ready to go Key On engine not running reading of 0 hertz