# emmision control question --pathfinder



## mikeralph7 (Dec 28, 2009)

is there a fuse between the ECM and the purge control valve(solenoid)?

where would this fuse be located?

i dont think i'm getting power to my purge control valve; how do i check for power? obviously power is not supplied at all times. when does the ECM supply power to it---after the car is shut off?

thanks


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## SPEEDO (Jun 9, 2003)

it is the purge control solenoid and not the purge volume control valve... right?
I have not found a good wiring diagram... yet


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## mikeralph7 (Dec 28, 2009)

SPEEDO said:


> it is the purge control solenoid and not the purge volume control valve... right?
> I have not found a good wiring diagram... yet


1999 Nissan Altima Problem Vacuum Cut Bypass Valve










in the picture it shows a fuse... i assume that this fuse exists. i've searched all over the internet looking for a possible location. any help would be appreciated.

thanks.


also, how would i go about testing for the 12volts?? should i look for the 12 volts after i shut the ignition switch off? is that when the ECM switches the current on? if not when does it?


edit: i used to hear loud clicking noises from rear of car near the emissions system (vapor canister) when i would turn the car off now i hear nothing. this makes me think the fuse is blown or the wire is bad


edit edit: my trouble code is P1441 --- vacuum cut valve bypass valve


i checked this part (vac cut valve--electric solenoid) and the purge valve--electric solenoid and they both work when i hook 12 volt up to them from the battery. the vacuum cut valve also works perfectly according to the following tests giving at this website:

http://www.justanswer.com/nissan/1h...-0-mil-dtc-p1441-vacuum-cut-bypass-valve.html










1. Plug port (C) and (D) with fingers.
2. Apply vacuum to port (A) and check that there is no suction from port (B).
3. Apply vacuum to port (B) and check that there is suction from port (A).
4. Blow air in port (B) and check that there is a resistance to flow out of port (A).
5. Open port (C) and (D).
6. Blow air in port (A) check that air flows freely out of port (C).
7. Blow air in port (B) check that air flows freely out of port (D).


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## mikeralph7 (Dec 28, 2009)

okay, i just ran a test on it.

i put the volt meter on it and got 12 volts with the ignition key in the on position

--and 13.8volts with the car running

is this the way the solenoids are supposed to be getting current?

i thought that they were supposed to receive current for approx 30 seconds whe the car is shut off... at that point the vapors from the canister get recycled somewhere???


anyone know????



at least i don't have an electrical problem


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## smj999smj (Jan 1, 2006)

Okay, first, there is not a fuse between the ECM and the Purge control valve. The fuse in the picture is to represent a test circuit with a fuse installed to do a componant check, in that case a vacuum cut valve bypass valve solenoid...which confuses me as to why you are asking about a fuse between the ECM and Purge Control Valve? 

Anyway, when your vehicle shuts off, it does not recycle the fuel vapors, per say. When your car is shut off, the vapors from the fuel tank get stored in the charcoal in the EVAP system's carbon canister. Later, when the car is driving, the purge valve will open and draw a vacuum, pulling the vapors into the intake manifold where they will enter the combustion chambers and be burned. The EVAP system also has the ability to self-check by closing the vent control valve at the end of the carbon canister and opening the purge valve to put a vacuum on the system, which is sensed by the EVAP pressure sensor, which takes the vacuum signal and converts it into DC voltage which it sends to the ECM to let it know if the EVAP system is sealing properly of leaking (where it will throw a code). 

You never mention a year of your Pathfinder. If you have an R50, what I would do is remove the canister and remove the vent control valve and shake it over some newspaper with the vent port facing down. Look for pieces of debris or charcoal coming out of the canister. If nothing comes out, it's a good sign, but if debris and charcoal does fall out, the inner liner has failed and you'll need to replace the canister and COMPLETELY clean clean out the entire EVAP system with compressed air. There is a TSB that describes how to do this properly. 

As far as your voltage readings, they are good. If you are reading battery voltage, obviously it will be a little higher once the engine is running and the alternator is charging as opposed to a static voltage of the battery. 

I would highly suggest (if my suggestions don't help) to find a copy of the factory service manual and do the diagnostic test for P1441.


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## mikeralph7 (Dec 28, 2009)

thanks for your answer. i've been slow getting on it because the whole thing is complicated and i'm taking it a little bit at a time.

something strange.... the Vent Control Valve works when i take it over to the battery and touch some 24 awg wires to it but it doesnt work when i jam the same 24 awg wire into the connector (the connector that it plugs into at the vapor canister) and then touch it to the leads on the solenoid of the valve -- yet i'm getting 12 volts on that connector.

that one has me baffled.

i'm going to ignore that for a while until i repeat it a few more times and see if i'm doing something wrong.....it's possible the wires weren't getting enough contact to support the current but just enough for me to get a voltage reading.


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## smj999smj (Jan 1, 2006)

You may not have ground at that connector as the vent control valve is normally open. The ECM grounds the circuit to shut the valve and test the system for leaks.


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