Another Code! P0449

Discussion in 'GM Powertrain' started by harristw, Oct 19, 2009.

  1. harristw

    harristw New Member

    Ok so our 07 Denali has been running just fine with no codes since the dealer replaced the Trans Internal Mode switch... until the CEL came on with a code of P0449. No other codes.. I understand its the Evap Control circuit stuck in an "open" state. The problem im having is that I dont have any visual reference to know what is in this circuit or where the components are located so i can start troubleshooting. Anyone have experience with this code and components?
  2. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    This problem is a circuit code. Very easy to troubleshoot with a scanner as you can operate the valve and watch the feedback to see what is and what isn't working. Without a scanner you are shooting in the dark. You can check for voltage and ohm check the solenoid. It's either a bad solenoid or a wiring problem between the solenoid and the PCM. A scanner makes this job a breeze and without it can be a real expensive experience.
  3. rf58

    rf58 Member

    my light is on same code -i had to go to Springfield il. a 100 mile trip the dealer said it wouldn't hurt. i filled up with shell silver and drove 65 and got the best milage i ever got.
    17 mpg.

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