What do you do when you checked and replaced everything and still get the code? Start from the beginning. SureTrack community member serviceguy had a GMC Sierra in their shop with an EVAP code of P0449 and after struggling to resolve it, they posed the question to the community, and with the help of fellow community member ironnutz and others, they were able to resolve the issue.
The following Real Fix summarizes the interaction between them in the community that led to the solution.
Vehicle
2009 GMC Sierra 2500 HD 6.0L
Title
Code P0449, Replaced White Wire
Complaint
Check engine light code P0449
Diagnostic Steps Performed/Parts Replaced
Command solenoid with scanner does not click. Has power to red wire terminal a. With test light between terminal A and B does not light up. I have replaced EVAP vent solenoid, PCM and white wire from solenoid to PCM and still has code. Checked gas cap looks good. I don’t know what I’m missing with replacing all these parts and still getting code. Even with new wire I still don’t get the test light to light up between A and B.
Best Answer from Community Member ironnutz
Do you get a ground signal at PCM on white wire when activating the solenoid? If so, the wire has a break somewhere. If not, bad PCM.
Cause
Bad white wire.
Correction
By replacing the white wire it cleared the code and the EVAP system works correctly.
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