Tech 2 help

[latvius]

I have a tech 2 but finding simple instructions on how to use it eludes me.
My blend door doesn't want to work. I have replaced the actuator now the brand new one doesn't move. Lower actuator to be precise I wanted to use the tech 2 to tell it to move but can't figure out how.

So my questions are on the pic I took
Should I be in diagnostics? What letter do I pick for a 2005 Tahoe?
I got to the section with all the actuators but have no idea what to do from there.

 

[George B]

Select K for your tahoe.
Going by memory here so..
Diagnostics>Body control module> hvac

Post a pic of that menu

 

[Doubeleive]

Are you 100% sure you got the right one? Some of the actuators look the same but don't work the same. So even though it will fit and plug in it won't work unless it's the right part number Best thing to do is to look at the old one you pulled out and match up the part number. If you really want to see if it's just not moving at all, just pull the HVAC fuse for a minute and then plug it back in and watch it this makes it recalibrate itself

 

[latvius]

Select K for your tahoe.
Going by memory here so..
Diagnostics>Body control module> hvac

Post a pic of that menu

After hvac it asks if I have dual climate which I do and after I select that I get the screen with all the doors,blower, actuators in the picture I included

 

[latvius]

Are you 100% sure you got the right one? Some of the actuators look the same but don't work the same. So even though it will fit and plug in it won't work unless it's the right part number Best thing to do is to look at the old one you pulled out and match up the part number. If you really want to see if it's just not moving at all, just pull the HVAC fuse for a minute and then plug it back in and watch it this makes it recalibrate itself

Well it replaces the one I got before which replaced the one I got before and maybe even one before that LOL so original part # is long gone. I've done the recalibrate several times, hence why I am trying to use a tech 2 to see what it is doing or at least what the computer thinks it is doing.

 

[George B]

After hvac it asks if I have dual climate which I do and after I select that I get the screen with all the doors,blower, actuators in the picture I included

Look for a special functions option

 

[Fless]

I have a tech 2 but finding simple instructions on how to use it eludes me.
My blend door doesn't want to work. I have replaced the actuator now the brand new one doesn't move. Lower actuator to be precise I wanted to use the tech 2 to tell it to move but can't figure out how.

So my questions are on the pic I took
Should I be in diagnostics? What letter do I pick for a 2005 Tahoe?
I got to the section with all the actuators but have no idea what to do from there.

View attachment 444097View attachment 444098View attachment 444099

Pick the 5th digit of your VIN. K=4wd, C=2wd

Like the start of this one: 1GNEK13R

 

[latvius]

OK that helps now I know where to look.

 

[latvius]

Found this doc, so if I read this right I need to go to
A/C Mix Door – Body > Heating and Air Conditioning > Special Functions > Output Test
And I guess this will make the mix door move (which I guess is the hot/cold blend door)

Another question am I supposed to have the vehicle running or no? Or does it matter?

 

[Joseph Garcia]

@swathdiver

 

[latvius]

I got this far but then after I got lost going that route into a section I can't figure out. I found a YT series on tech 2 for dummies but it is for a saab, I will prolly watch it and see if I can learn anything.

 

[swathdiver]

If you were to click on F2, then on that menu there would be functions above the hard buttons below the screen. Those would say to open or close or make it colder or hotter, etc.

So you press those to test the actuator and can see other lines showing it in action moving through 0-255 counts or 255-0 counts.

After installing the new actuator did you perform a relearn? I leave the engine running doing these tests so the battery doesn't go dead.

 

[Fless]

Although those buttons are "hard" they're technically known as soft keys, since their functions change by what's shown above them on the screen.

They pair up with the screen info, like this:

 

[latvius]

Ok I just learned these are the function keys lol.
I'll go back in tomorrow and press f2 and go from there.
I haven't done a relearn from tech 2 was just disconnecting battery.

 

[latvius]

Although those buttons are "hard" they're technically known as soft keys, since their functions change by what's shown above them on the screen.

They pair up with the screen info, like this:

View attachment 444210

I actually figured that part out but I ended up on that same screen and couldnt figure out where to go from there. I guess those counts are error counts?

 

[Fless]

I actually figured that part out but I ended up on that same screen and couldnt figure out where to go from there. I guess those counts are error counts?

No, not error counts. The "actual" count should closely match the "commanded" count; the actual is the position of the door. Compare the two associated positions and know that a small difference is okay. That tells you that the computer is commanding the door to be at "x" position and the actual should be close to the same number.

In your pic the mode door is only one count off of the commanded position (83 vs 82, respectively). Much joy!

 

[latvius]

No, not error counts. The "actual" count should closely match the "commanded" count; the actual is the position of the door. Compare the two associated positions and know that a small difference is okay. That tells you that the computer is commanding the door to be at "x" position and the actual should be close to the same number.

In your pic the mode door is only one count off of the commanded position (83 vs 82, respectively). Much joy!

OK gotcha, that makes sense

 

[Joseph Garcia]

@latvius I have a couple of Tech 2 User Guides, one specifically for GM vehicles. The files are too large to upload to this Forum, but if you PM me your email address, I can send them to you.

 

[latvius]

OK I learned some more, now what does the comand state on and off do or supposed to do?

 

[Fless]

Command it OFF and see if the counts go to 0?