MTG2500 com issue with HVAC on 2002 GMC 2500 Sierra HD

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • bbvette
    Junior Member
    • Oct 2013
    • 4

    MTG2500 com issue with HVAC on 2002 GMC 2500 Sierra HD

    Hi, I have a new to me 2002 GMC Sierra 2500 HD with 8100 Vortec 496 engine, and an MTG2500 with the latest available load version 9.2 on both the VCI and TSI programmable carts. It all works, except when I try to communicate to the check HVAC codes, and diags, it says no communications. All other engine and transmission paths work just fine.

    I am wondering if I have and ECM issue to the HVAC or if the MT2500 code in version 9.2 did not cover this interface. Thx if anyone can let me know, I am using no keys in the in line adapter per the scanner saying no key is required.

    Thx, Craig Schultz
  • maven
    Senior Member
    • Mar 2014
    • 269

    #2
    The base HVAC system on your truck is not on the Class2 network.

    If you have auto HVAC you'll need to check it with a different tool, I don't know if the 2500 covers it.

    Comment

    • GM guy
      Senior Member
      • Dec 2006
      • 122

      #3
      hvac comm

      The newer keyless platforms should comm. Does your mtg2500 have a hvac selection on menu?, if so what personality key using? I am thinking 9.2 did not yet have coverage for hvac. I believe by 14.2 they go back to 2000 M.Y. for hvac.
      HTH

      Comment

      • bbvette
        Junior Member
        • Oct 2013
        • 4

        #4
        Ahhh.......thx, so it sounds like some of this requires a GM Tech2 or some of the newer Snap On tools......originally on the old red carts, I was using key K9 I think, maybe K13, can't recall on the GM. But now with the black programmable carts at latest 9.2 code for 2500, it says no key required..........thx. Craig

        Comment

        • bbvette
          Junior Member
          • Oct 2013
          • 4

          #5
          Originally posted by GM guy
          The newer keyless platforms should comm. Does your mtg2500 have a hvac selection on menu?, if so what personality key using? I am thinking 9.2 did not yet have coverage for hvac. I believe by 14.2 they go back to 2000 M.Y. for hvac.
          HTH
          Thanks for the clarification. I am a hobbyist at home, and have used the MTG 2500 successfully on most of my personal cars. Since this truck is new to me in the past two weeks, I just ran through all the menus to check everything out.......and there is an HVAC list presented, to check for both codes, and run diagnostics. Now that is not to say they actually have code behind those menus for this specific vehicle, even though the menus are there. Maven mentioned there was not a comm path for scanners to the HVAC on the base model, which makes a lot of sense, it probably has no electronic controls in this model. I was going by the menus on the snap on, which are probably set up for many vehicles and probably are not applicable to this model.

          I may have an issue on my truck right now though, it seems the AC is very cold on max, and then the little detent warmer, it warms up too much, and is barely cool. So I am thinking I may have some calibration issues and heard this truck has some electronic controls, but it is the base HVAC with rotary dial, not the electronic temp control so I may be mistaken about any electrionic calibration here. Thx again guys for the pointers!........Craig

          Comment

          • bbvette
            Junior Member
            • Oct 2013
            • 4

            #6
            Originally posted by maven
            The base HVAC system on your truck is not on the Class2 network.

            If you have auto HVAC you'll need to check it with a different tool, I don't know if the 2500 covers it.
            Thank you for the post, I have the base HVAC cooling with rotary temp knobs and the standard controls for sending the air through the various ducts, not the electronic versions with temp settings. I suspect this means it is very similar to my 97 Silverado, without electronic stuff. I am having a minor issue with the temp granularity in AC setting, it has a detent at the max position my 97 did not have. I can hear the duct door flop when I move it a touch warmer, like it moves too far quickly, and I get air in this position that is barely cool, too much heat in the mix. If I move it more, it does get way hotter, as the heater core air moves in. However, it still seems to need some tweaking in the next to max setting to allow more tempering of the air temp like my 97 silverado which did not feel warm in AC setting until mid scale, versus right near the max setting on my new 02 GMC...........Craig

            Comment

            Working...