P0449 2009 Chevy Tahoe

I have a 2009 Chevy Tahoe Z 71 5.3 engine. I am having difficulties with this code.P0449 I am assuming it is either the PCM or the white wire from PCM to solenoid I am getting power even with the key off to the red wire. I am not getting anything to the white wire, Has anybody dealt with this issue? Would greatly appreciate help

 

Leave the vent valve connected. You said the red wire has power, great. With the vent valve connector still plugged in, back probe the white wire. It should also show battery voltage. If not the vent valve is no good. If there is power, move to the PCM connector x1-pin 61 (same white wire). With that wire back probed and the vent valve connected, there should also be battery voltage. If not, the problem lies in the white wire between the computer and the vent valve. If it isn't easy to find, I wouldn't hesitate to just splice in a new wire.
 

I did replace the vet valve solenoid, but I am going to run this test tomorrow and check voltage with it plugged in. Thank you for your response. I will keep you posted on the results.

OK, so I do have 12 V on the white wire with the sensor plugged in while back probing what is the next step I can take to figure out this problem

Check it at the PCM, as Noah suggested. Do you still have 12 v with the key out of the ignition on the Red/White wire as you stated before?

Grew32467 wrote:

OK, so I do have 12 V on the white wire with the sensor plugged in while back probing what is the next step I can take to figure out this problem

If you're to measuring at the vent valve connector, then repeat the test at the PCM connector x1 pin 61.
If you do indeed have voltage at that point, my next test would be to command the vent valve closed with the scan tool and watch for that wire to switch to ground.