Hi im a new member and I hope I'm not asking for too much. I was reading a post regarding P0447 someone suggested there s fuse/ junction box in the glove box area. Is it possible for anyone to post a picture because I removed every single panel in there and could not find anything that resemble a fuse box. Maybe a picture will help.
Issue: I have 12v (+)at the connector with the switch on but no ground. I check pin 105 going to the ECU and there's continuity with the connector just no ground even when the switch is on. This thing is driving me crazzyyyy!! I already failed inspection and only have a few days left with my rejected sticker.
Please help..

 

The only J junction fuse box is on the driver side, (below the steering wheel and to the left outter edge of the dash) there is no fuse box inside the cab near the glove box.

P0447 is the evap control valve which in most cases requires replacing when it gets stuck either in the open or closed position, and it is located by the charcoal cannister up under the wheel well on the rear driver side of the car

 

The EVAP Canister Vent Control Valve is probably bad. They have a habit of corroding and cannot work. Check the operation of the valve according to the FSM, page 387.

http://boredmder.com/FSMs/Nissan/Maxima/2002/EC.pdf

 

SOrry. I replace the valve the code still come. I realize power is not getting to the valve, because when I tried it manually with a 12V power supply, I can hear the clicking noise and it's air sealed. I use a multimeter at the connector I get no voltage. + side is good, just no ground. I traced the ground/signal back to the ecu, there's continuity. Could it be my ecu is bad?

 

The EVAP Canister Vent Control Valve should have 12 volts on the red/yellow stripe wire whenever the ignition key is in the ON position.

The ECU supplies ground on the orange/blue stripe wire when necessary.

You said you have the 12 volts and that the wire between the EVAP Canister Vent Control Valve and the ECU has continuity.

With the connector plugged onto the EVAP Canister Vent Control Valve and the ignition key on, does the orange/blue stripe wire always measure 12 volts or does it go to ground?

 

No, the orange/ blue stripe didn't work. I got the ground from a screw bolted to the body. So with key turned on, I had my 12v from one side of the connector that goes to the control valve ( i believe it's a brown color not sure) and ground from body. The ECU failed to supply the ground I guess.

 

The way you tested for 12 volts is ok.

But but the orange/blue stripe wire that supplies the ground to make the solenoid work (this is the wire that goes to pin 105 of the ECU). You said that you checked the continuity of this wire and I want to verify that you had one meter lead on pin 105 of the ECU and the other on the orange wire in the connector for the EVAP Canister Vent Control Valve and the meter was set to measure ohms.

Assuming that you did, the only way to tell if the ECU is grounding the orange wire is to have all connectors plugged in. With the ignition key turned on, you will have 12 volts on the red wire (the one you say looks brown) of the EVAP Canister Vent Control Valve. If the ECU is not supplying ground to the solenoid, you will measure 12 volts on the orange wire and pin 105 of the ECU. If you measure zero volts (or almost zero), then the ECU is working.

 

That's what I did to test for continuity.
I'm a little confused on paragraph 2.

Now I must say that I have P1800 also. Can that be a factor in not getting ground from the ECU to the evap vent valve?

 

I'm pretty sure that the P1800 doesn't have any bearing in the P0447.

What I was trying to say in paragraph 2 is that even though you have checked continuity of the one wire, you still need to check it electrically/functionally.

Hook the voltmeter to pin 105 of the ECU and turn on the ignition key. If the ECU is not working, i.e., not trying to activate the EVAP Canister Vent Control Valve, you will measure 12 volts at pin 105. If the ECU is working, you will have zero volts on pin 105.

Should you have zero volts on pin 105, then check the voltage on the orange/blue stripe wire at the EVAP Canister Vent Control Valve. Since this comes from pin 105 of the ECU, the voltage should also be zero. If there is a difference, the wire is bad.

The only thing is, I don't Know if pin 105 of the ECU is supposed to be zero volts all the time or if it goes on and off.

 

I will try that and let you know i find.

 

So I measured the voltage sure enough it was zero, whether the switch was on or not. The other thing I noticed was, I had close to 16V on the brown pin using another ground. Could that be the issue?

 

Did you ever figure this out?

I got an 0447 recently and found the wiring pretty much broken off at the connector. Found a connector at the wreckers, soldered it on and still no luck, same code.

Just grabbed a vent valve from the wreckers but I feel like it's not gonna work.

Gonna go pop it in and see, I'll report back.

 

No dice with the used evap valve.

Here's some info I find kinda strange...

If I clear the cel, it will stay off until I shut the car off but as soon as it is restarted it's right back.

Before it's shut off, it will show a pending code but no light, no matter how long it's running. If I clear the pending code and shut it off before it comes back, there's no light when I restart it, just a pending code eventually.

How do I check the valve

 

Ok so I have continuity between pin 105 and terminal 2, 12v at terminal 1 and 0v at terminal 2 with ignition on, and both valves are good when bench tested.

Still have the light, I'm lost...

 

When you changed parts, did you reset the ECU to turn off the check engine light?

 

Stuck here also!