Question about 2004 Chevrolet Avalanche

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I have a avalanche 2004 and I got a code P0446 I have had it reset a couple of times now it wont reset what do I need to replace?? where do I start

The engine light is on code P0446 they say vac code , charcoal canister and a couple of other things to do with vac ..what is common on these and what is the first thing I should replace?? HELP PLEASE

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Melinda, I would recommend having a evap test performed. The tech would do a smoke test for possible leaks, and an on/ off test on the vent valve. Often times the vent valve is faulty. The parts are in stock at Napa.

Posted on Nov 20, 2014


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Posted on Jan 02, 2017

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SOURCE: 96 corsica error cod po441 no purge flow

Look, that code means:
P0441 - Evap emission control system Incorrect purge flow

so try to replace the emission control.

Posted on Jun 19, 2008

  • 1990 Answers

SOURCE: 1998 toyota corolla dtc# p0441 and p0446

Yes it would cause these Codes.

Posted on Jan 15, 2009

  • 6674 Answers

SOURCE: check engine light on,results in code P0446-fuel emission cotrol

Well it could be as simple as a new gas cap, or clean seal on it & tighten again. There are a few other items in the system too, but one common one is the vapor canister gets plugged up with dust & dirt.

Posted on Apr 11, 2009

  • 104 Answers

SOURCE: I have a 2004 Avalanche, 49K mileage, code PO446,

That is an EVAP code. its a vent control code. you can manually test it by powering it up if you know where its at. i cant remember exaclty where its at off the top of my head but its only 2 wires. using a volt meter you want to make sure power is getting to it, but you cannot activate it without dealer scan tool.hmmm if you can figure out which is ground and power when you give it 12 volts it should click. meaning your vent solenoid works and you have wiring problems or its leaking.

EVAP problems are hard to finde with out scanners. you can change the vent solenoid and hope it fixes it. but a code points you to the direction of a problem. hopefull its not wiring problems. in the northern states with snow. ice can pull out wires and also get clogged in the vent solenoid and lock it up. its either wiring or bad or a leaking solenoid. check condition of wires. if they look good try a vent soleniod.

if that doesnt fix it after a engine light reset and 2 weeks or so. then goto dealer. you need to reset it after repair. light will not go off on its own.GOOD LUCK

ASE certified.
plz rate

Posted on Apr 29, 2009

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SOURCE: code p0446 keeps coming on

What does that mean?

Evap vent valve has only one purpose. It closes in order to seal the vent so the EVAP system can pressurize and ensure there are no leaks. Evap vent valve is usually supplied Batt. voltage with key on. The ECM's driver controls the ground, and when grounded, activates the valve (closing it). If the ECM detects a short to ground, and open,or a short to battery voltage on the control circuit, P0446 will set. Code also may refer to ECM detecting that EVAP system is unable to achieve or maintain vacuum during test.

There will be no obvious symptoms to driver, other than MIL illumination.

A code P0446 could mean one or more of the following has happened:

* Faulty vent valve
* Open, short or excessive resistance on Vent valve control circuit
* Blockage of vent valve
* Bad PCM

Possible Solutions

With a P0446 OBD-II trouble code, here are some things to try:

* Replace Vent valve
* Repair open, short, or resistance problem in control circuit
* Repair open, or short, or resistance problem in power circuit
* Replace PCM

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Posted on Sep 05, 2010

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