The solenoid is up front of the engine, just in front of the alternator. You can reach it by hand, no screws or bolts, you will need a long screw driver with a flat blade to shimmy the hoses loose and the clip edge on the solenoid back. You must reach it from below, you will need ramps or jack stands to hold the car up. There is a clip on top of the electrical connector, i broke mine but thats ok. do you have a V6?,,,,,,,,once your car is jacked up, you can go under and see the diverter valve plainly in front of the engine, there is a flexible hose coming from the air pump that you can pull off the valve to check for air to the valve.
you can reach the diverter valve from the driver side and the solenoid from the passenger side. check for vacuum on the charcoal canister w/engine running. remove line and feel for vacuum, if ok then the other side to the solenoid should be good too. both devices use the same vacuum port.
once the vac line was taken off the solenoid and connector to the valve, i pulled them up to engine level and checked for vac. It was good.