GMC Sierra 1500 2wd 4.8V8 Reg. cab

[Archie1919]

Hi GM Tech,

I'm new to this site, and need to ask a question.

My 2000 GMC Sierra regular cab 1500 4.8L 2wd keeps throwing the code P0446.

So I threw back at it a new gas cap. Next day the SES light came back on. Same code. I read Roy67ss post for Nov. 17, 05 which gave me alot of info, but the p/n 15750484 for the vent valve doesn't match up with a 2000 sierra.(didn't think it would)

Here's the story on my truck: I bought it from my uncle last year with only 2500 miles on it. It was stored for 5 years(yeah, it's like new!). I live in the city, no country farms or off roading, just clean...smog....so I wouldn't think the valve would get clogged, maybe just old. The SES light started coming on a few months after I got it, and progressively has come on more frequently. I can't find a part # or the proper name of the valve. Is the valve called something else for my truck, or am I looking in the wrong direction for fixing this problem?

Oh, yeah, My milage has only been about 14mpg. I think it should be alittle better. Could this vent valve affect my milage a little? Otherwise, it drives like a brand new truck!

 

Thanks! What a great site!

[GM-Tech]

This is probably what you need. Part #'s are listed at the end of this. sorry, the photos in the TSB do not carry over in a cut/paste...

 

 

Subject: DTC P0446 (Restricted/Blocked EVAP Vent Path) Set, Service Engine Soon (SES) Lamp Illuminated (Replace Evaporative Emission (EVAP) Vent Valve Solenoid Assembly with Service Kit) #02-06-04-037B - (10/16/2006)

 

 

Models: 1999-2007 Chevrolet Silverado Models

 

1999-2007 GMC Sierra Models

 

 

 

 

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This bulletin is being revised to add model years and update the correction information. Please discard Corporate Bulletin Number 02-06-04-037A (Section 06 -- Engine/Propulsion System).

 

 

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Condition

Some customers whose vehicles are operated in dusty type environments, such as farming or mining off-road type applications, may comment about the illumination of the instrument panel SES light, with a DTC of P0446 (Restricted/Blocked EVAP Vent Path) being set.

 

Cause

Dirt and dust intrusion into the EVAP canister vent hose assembly, resulting in restricted air flow, may cause this condition.

 

Correction

After following the Service Information diagnostics for P0446 and determining that the EVAP canister vent valve is the cause of the SES light, replace the existing EVAP canister vent valve assembly with a new assembly. This new assembly is a sealed unit that is designed to be vented through a remote filter box. To ensure correct installation, follow the procedures below.

 

1999-2003 Model Year (Use Service Kit P/N 19152345)

Raise the vehicle. Suitably support the vehicle.

Disconnect the EVAP canister vent valve electrical connector, if equipped.

Disengage the two vent valve pipe clips securing the pipe to the underbody. Remove the clips from the underbody and discard.

Disconnect the vent valve pipe at the EVAP canister.

Remove and retain the EVAP canister vent valve bracket mounting bolt.

Remove the complete EVAP canister vent valve assembly with bracket attached and discard.

 

 

 

Important: The new canister vent valve will be installed in a new location, outside of the frame.

 

Position and secure the new valve assembly to the frame bracket on the outside of the frame using the existing hole and mounting bolt.

Tighten

Tighten the bracket mounting bolt to 12 N·m (106 lb in).

 

Connect the vent valve pipe to the EVAP canister.

Install the two vent valve pipe clips into the existing underbody holes.

Connect the EVAP canister vent valve electrical connector, if equipped.

Attach bulk 5/8" heater hose to the vent valve port and secure using a clamp. Run a length as needed along the frame rail routing to the area above the transmission.

Cut the hose to determined length and install the supplied filter box. Secure using a clamp.

 

 

 

Secure the filter box to the fuel lines above the transmission using a tie strap. The filter box opening should be pointing downward.

Tie strap the hose as needed along the frame rail in order to keep the hose away from pinch-points and heat sources.

Lower the vehicle.

2004-2007 Model Year (Use Service Kit P/N 19152349)

Raise the vehicle. Suitably support the vehicle.

Disconnect the EVAP canister vent valve electrical connector.

Disconnect the canister pipe from the vent valve.

Push in the retainer and remove the existing canister vent valve from the fuel tank clip or mounting bracket. Discard the old valve.

Cut back the existing canister pipe approximately 51 mm (2 in) to remove the quick connect end.

Crew Cab Short Box Shown Below, Other Configurations Similar

 

 

 

 

Extended Cab Short Box Shown Below, Other Configurations Similar

 

 

 

 

Install the new canister vent valve to the fuel tank clip or mounting bracket.

Cut bulk 5/8" heater hose to a length of approximately 76 mm (3 in). Install the hose between the vent valve and the canister pipe and secure using clamps.

Attach bulk 5/8" heater hose to the vent valve port and secure using a clamp. Run a length as needed along the frame rail routing to the area above the transmission.

Cut the hose to determined length and install the supplied filter box. Secure using a clamp.

 

 

 

Secure the filter box to the fuel lines above the transmission using a tie strap. The filter box opening should be pointing downward.

Connect the EVAP canister vent valve electrical connector.

Tie strap the hose as needed along the frame rail in order to keep the hose away from pinch-points and heat sources.

Lower the vehicle.

Parts Information

Part Number

Description

Qty

Material Allowance

 

19152345 (1999-2003 Model Year)

Solenoid Kit, EVAP Emission Canister Vent Valve 1

--

 

19152349 (2004-2007 Model Year)

Solenoid Kit, EVAP Emission Canister Vent Valve

1

--

 

9438383 (5/8" X 25' roll)

Hose

Cut to Length

$10.80 USD ($22.59 CAD)

 

12337820 (10 per pack)

Tie-Strap

5

$3.80 USD ($4.55 CAD)

 

15620999 (10 per pack)

Clamp

2 (1999-2003)

 

or

 

4 (2004-2007)

$3.78 USD ($7.08 CAD) (1999-2003)

 

or

 

$7.56 USD ($14.17 CAD) (2004-2007)

 

 

Put unused material on shelf for future use.

 

Warranty Information

For vehicles repaired under warranty, use:

 

Labor Operation

Description

Labor Time

 

J7908*

Solenoid, EVAP Emission Canister Vent Valve - Replace

0.6 hr

 

* This is a unique labor operation number for use only with this bulletin. This number will not be published in the Labor Time Guide.

 

 

 

 

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

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