02 Legacy GT

[Lurch]

My CEL light has been on for quite some time. I have procrastinated too long

 

the Code I'm getting is P0447 (Evaporative Emission System Vent Control Circuit open) I replaced the Vent Valve some time ago and the CEL light has never turned off. After doing some research I'm thinking its the Canister Purge Valve or a leak somewhere in the lines(tubes)???? However, I can't find said Valve. So my questions are:

1) Where is the Canister Purge Valve located on a 02 Legacy GT AWD?

2) Any other ideas what might be the issue?

 

 

I'm a Newbie so take it easy. I bought this as a Damaged or salvaged Title so there might have been some sketchy work done me.

Edited July 6, 2019 by Lurch

[Lurch]

I found the purge valve, right where I was looking all along. I was looking for something much bigger. It was hidden under the exhaust manifold on the passenger side. now onto testing it.

[RumbleRumble]

yeah it's a pain to find. I've had to replace both vacuum hoses that run off it which is even a bigger pain.

[Lurch]

yeah it's a pain to find. I've had to replace both vacuum hoses that run off it which is even a bigger pain.

 

Did find a leak or just replace the hoses because you didn't want to bother searching?

To be honest I'd rather it be the vacuum line than an electrical problem. I have almost zero confidence in my electrical troubleshooting abilities.

[Lurch]

After tinkering around It seems like it is, in fact, an electrical problem! which brings me to my next question. (Though I still haven't ruled out the Purge Valve)

The is no voltage reading at the plug to the vent control valve(near canister)with the engine on or off. I'm assuming that it's either because the wiring is damaged upstream or the ECU only sends voltage when it needs to or wants to test things?

 

Is there a way to force the ECU to trigger the Vent Control Solenoid? So that I can test to see if voltage is reaching the plug when it's triggered?

 

Or is my logic totally wrong?

[doublechaz]

You're right. You could either use a jumper wire to the solenoid to check if it is seized, or you can wait for the ECU to send the signal.

 

I've never done it, but I hear there is a pair of green connectors somewhere by the driver's shins. They are test connectors. Normally they are not connected, but you can connect them and then I think you put the key in run. The ECU then flips a lot of things off and on so you can check them. When you're done you key off, undo the connectors and you are back to normal.

 

For some stuff like solenoids you can just listen for them to click as they flip flop, others you would have to probe for voltage, or if you have voltage, but no action at the solenoid you would know it was seized.

 

Do you have a service manual? I'm sure it goes into great detail about all this, but mine is a scanned pdf, so there is no search, it's all just a sequence of big images.

[Lurch]

Update: I did the green connector test and use a component tester on the Vent valve. It isn't opening while performing the green connector test but worked fine when I tested it with the component tester.

So I think my fear has come true, there must be a problem with the electrical somewhere between the ECU and the plug at the for the vent valve.

I'm planning on starting from the plug and going back until I find the problem. I'd also like to test it right from the ECU before I pull all the wiring out. Does anyone know where i can find a diagram or map of the ECU wires? So I can locate the right wires and test them on that end.