Yukon Denali AWD V8-6.2L (2007)
Evaporative Canister Filter: All Technical Service Bulletins
Emission - MIL ON/DTC's P0442/P0446/P0455/P0449
TECHNICAL
Bulletin No.: 09-06-04-028C
Date: April 07, 2011
Subject: Malfunction Indicator Lamp (MIL) Illuminated, DTCs P0442, P0446, P0455 or P0449 Set - Fuel Tank Hard to Fill - Moisture, Water,
Corrosion at Evaporative Emissions (EVAP) Canister Vent Solenoid (CVS) Valve (Install Revised EVAP CVS Valve Assembly and Jumper Harness)
Models:
2007-2010 Cadillac Escalade, Escalade ESV, Escalade EXT
2007-2010 Chevrolet Avalanche, Suburban (1500 Series), Tahoe
2007-2010 GMC Yukon, Yukon XL (1500 Series), Yukon Denali, Yukon XL Denali
Excluding 2008-2009 Hybrid Utility Vehicles
Attention:
The revised Evaporative Emissions (EVAP) canister vent solenoid (CVS) valve assembly comes with two tie-straps attached. These two tie-straps will
be used to attach the EVAP CVS valve vent pipe to the fuel tank filler pipe.
Supercede:
This bulletin is being revised to add an Attention statement and update the Subject, Correction, Parts and Warranty Information. Please discard
Corporate Bulletin Number 09-06-04-028B (Section 06 - Engine/Propulsion System).
Condition
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Some customers may comment that the fuel tank is hard to fill.
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They may also comment that the malfunction indicator lamp (MIL) is illuminated.
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Upon investigation, one or more of the following DTCs P0442, 0446, P0455 or P0449 may be set as Current or in History.
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During diagnosis there may be evidence of water intrusion at the evaporative emissions (EVAP) canister vent solenoid (CVS) valve.
Cause
The EVAP CVS valve draws fresh air into the EVAP system through a vent attached at the top of the conduit that is secured to the fuel filler pipe. Under
certain operating conditions, dirt and dust intrusion into the CVS fresh air intake/venting system may result in restricted air flow.
Under certain operating conditions, if water is ingested into the EVAP CVS fresh air intake/venting system, it may reach the CVS valve causing
corrosion in the CVS valve and may cause restrictions in the fresh air intake path when the CVS valve is in the closed position.
Ingested water will also collect in the CVS valve cyclonic filter in order to protect the EVAP canister. However if the capacity of the cyclonic filter is
exceeded, this may result in water entering the EVAP canister and cause an additional restriction during refueling.
Correction
Note
DO NOT replace the EVAP canister assembly for this concern unless it fails the leak test or it has ingested excessive amounts of dirt, dust or water.
After following the published SI diagnostics and determining that the EVAP CVS valve is the cause of the MIL illumination or the hard to fill symptom,
replace the existing EVAP CVS valve assembly with the new revised design assembly.
This revised EVAP CVS valve assembly is a sealed unit that is vented through a remote pre-filter that is designed to be mounted atop the fuel filler
housing. To ensure correct installation follow the procedure outlined below.
1. Turn OFF the ignition, and all electrical components, including the scan tool.
