On a 2005 Malibu 3.5, check engine light is on and it gives a message to check gas cap. We have replaced the cap, no change. It shows a PO449 code on the scanner. Can anyone give me some tips on troubleshooting this? Or the most likely defective part? Any help is appreciated...

 

this dtc sets when the commanded state of the driver for the solenoid does not match the actual position of the solenoid. There is an electrical fault. follow tsb #PIC4661A to inspect for a damaged wiring harness.

the harness comes out of the right rear floor pan area at connector # 413. The harness is located in front of the EVAP canister.