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.