hi everyone i have a code p0449 i checked for voltage at the solenoid there is voltage but no ground................does anyone have a diagram of the pcm and what connector and pin the ground comes from Thanks

 

year make model engine

 

06 trailblazer 4.2

 

there will not be grd on this wire unless the vent solenoid is commanded closed by the pcm. this only occurs when the pcm runs a leak test. the vent is normally open. if you have a scan tool with bi-drectional controls; command the vent closed and check for grd using a test light across the 2 pins of the vent solenoid connector....use a conventional test ligh with a bulb not led...this provides a load to test the circuit.

before you check the grd wire...make sure the solenoid works.
vent solenoid wiring connected....key on to provide power to the vent solenoid....provide grd using a jumper wire. if the solenoid doesn't click on and off when powered and depowered...the fault is in the solenoid.

the pcm c1 connector pin 22 white wire in the grd control for the vent solenoid.