This 2006 GMC Yukon came in with the Service Engine Soon (SES) light on and a code P0449 stored in the PCM memory.
This test should be done on the vehicle but I could not figure a way to o the test and position everything for a good picture. So you will just have to imagine this is still in the vehicle. Connect an ohm meter across the two solenoid terminals and measure the resistance. This one is open so I know it is bad.
In further testing there should be battery voltage on the orange wire, terminal “B” at the red harness connector. The PCM applies a ground to the white wire, terminal “A”when operational conditions have been met. The Canister Vent Solenoid Valve is located at the rear of the fuel tank as shown below. Be careful when working with these parts. As they age they will become brittle and may not be replaceable. This of course refers to the hose and electrical connector.
To remove the hose the two ends have to be squeezed together in order to release the locking tabs. I find it easier to slide a small pocket screwdriver into the hose fitting to release the locking tabs.
Once the tabs are released the hose has to be pulled and rotated to remove it from the solenoid assembly.
The electrical connector is located on the left or driver’s side of the solenoid.
It has a thumb latch that has to be lifted while the connector is pulled away from the solenoid.
There is a metal locking tab on the mounting bracket that will bend out easily as shown below.
Then the solenoid can be slid back and off of the bracket.
The new canister vent solenoid valve installed.
I cleared the code with my Tech 2 scan tool and switched the ignition on and back off several times to allow the PCM to do it’s self tests of the solenoid. It passed and this one is done.