1997Max P0446 evap vent valve circuit fault?

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

Yorkmint - 22 Apr 2004 13:36 GMT

What the heck is this? Code reader comes up as above, check engine light codes
at 903, which is the same fault. Haynes manual doens't even show an evap vent
valve in the schematic, only a purge valve. Changed gas cap already, reset
code. It came back on in 8 miles. Where is it, what does it do, and how do I
fix it?

Reply to this Message

dave stone - 22 Apr 2004 15:28 GMT

> What the heck is this? Code reader comes up as above, check engine
> light codes at 903, which is the same fault. Haynes manual doens't
> even show an evap vent valve in the schematic, only a purge valve.
> Changed gas cap already, reset code. It came back on in 8 miles.
> Where is it, what does it do, and how do I fix it?

I have a 97 Maxima and the CEL light came on about 3 days ago with the 09 03
code.

I thought it was the EVAP Canister Vent Control Valve?

Here's an old post from this NG I copied and pasted:

From: Daniel B. Martin (daniel88b88martin@juno88.com)
Subject: Re: need help locating the EVAP canister
View: Complete Thread (2 articles)
Original Format
Newsgroups: alt.autos.nissan.maxima
Date: 2001-04-30 04:40:07 PST

> As i was driving tonight my check engine light came on in
> my 97 maxima. The error codes are 0705 (evap small leak)
> and 0903 (EVAP canister vent control valve). Can anyone
> tell me where the EVAP canister is?

<<snipped>>

Diagnostic Trouble Code 0903 points to a problem with the EVAP Canister Vent
Control Valve. EVAP = EVAPorative emissions control system. This is the
system which seeks to minimize air pollution which results from evaporation
(as opposed to incomplete combustion) of gasoline.

The EVAP CVCV is located on the EVAP canister (underneath the vehicle near
the left rear tire) and is used to seal the canister vent. It has one hose
connection and one two-wire electrical connector. The solenoid in the EVAP
CVCV responds to signals from the ECM. When the ECM sends an ON signal,
the coil in the solenoid valve is energized. A plunger then moves to seal
the canister vent. The ability to seal the vent is a necessary part of the
diagnosis algorithms for other evaporative loss system components. This
solenoid valve is used only for diagnosis, and usually remains open. When
the vent is closed, under normal purge conditions, the evaporative loss
system is depressurized allowing "EVAP Control System (Small Leak)"
diagnosis. Since this part is used only for brief emissions tests the
vehicle will usually start and run well despite a Service Engine Soon
warning light on the dashboard.

The EVAP CVCV may be bench tested. Remove it from the vehicle (one hose,
one connector, two bolts). Verify that air may pass freely through the
valve. Then use a pair of fused test leads to apply 12 volts to the
terminals to energize the solenoid. Verify that air does not pass freely
through the valve. If the CVCV fails these tests, try cleaning it with
WD-40 and compressed air. If this fails to free it up, replace the valve.
When you install a CVCV (the original or a replacement) always use a new
O-ring.

Daniel B. Martin
Nissan owner and D-I-Y mechanic

----------------------------------------------------------------------------
----

--
http://www.anti-leech.com/spam/spambot_stopper.php

Reply to this Message