[Thaniel]

Bought my car (2011) with a check engine light. The code that wouldn’t go away was P2418. Evap switching valve. Using GDS2 (see screen shot) it looked to me it was an electrical issue. Probably in the valve itself. The valve is packaged with the evap pump. So I order one and plug it into the car to test. Just to make 100% sure this will fix the error before installing completely. Nope. Same. Guess it isn’t that. Not what I had expected.

So I dig out the multi meter
And check the input voltage. Pin 5 on the connector if I remember right. The voltage quickly fades to 1v. Check the voltage on the pump power in it is correct. The two are supposed to be tied together at a junction point somewhere in the harness. Also at this junction the vent valve supply is connected. I test by bridging the vent valve supply to the switching valve supply. Yup error goes away. Looks like something happened in the wiring harness.

I open up the wire harness to find the junction point. The repair manual said it was a little over 7 inches past a certain connector. At more than 8 inches of unwrapping I still wasn’t seeing it (see other pic). So I permanently solder the switching valve voltage supply to the voltage supply of the vent valve (larger of the three wires and not likely actuated at the same time). Volia fixed. Now I have a new pump/switching valve that is not needed.

Expect my car isn’t unique. Maybe this will be the problem on another persons car.

 

[SNESntMlnial]

I have a 2011 with similar issues. It's throwing a P2400 and P2418 code. I've replaced both solenoids, one under the hood, and one in the EVAP assembly, the leak detection pump, the evap canister, and the gas cap. I've also cut away the harness sheathing to look for corrosion. Can't keep the codes from coming back after a power cycle.

I'm going to try and follow this procedure. Do you have any images of the finished work?