P0449 Code - GMC Acadia, Sierra

GMC Tech Tip: EVAP Vent Solenoid Replacement (P0449)

Check engine light is illuminated with code P0449 from scan tool (Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction).

Model: 2009 GMC Sierra

Complaint

Check engine light is illuminated with code P0449 from scan tool (Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction).

Situation

  • The solenoid does not respond to scan tool command.
  • The solenoid has power to A-terminal red wire.
  • Test light between terminals A and B does not light.
  • EVAP vent solenoid was replaced along with white wire from PCM to solenoid; code still appears.
  • Gas cap seals properly.
  • New wire does not allow test light to illuminate.

Solution

Test for a ground signal at the PCM on the white wire while activating the solenoid. If a ground signal is present, the wire has a break in it and needs replaced. If the signal is not present, the PCM module is faulty and needs replaced.

Courtesy of Mitchell1 SureTrack Real Fix.

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