Emissions - SES Lamp ON/DTC P0446 (EVAP) Set
Bulletin No.: 03-06-04-037Date: July 31, 2003
TECHNICAL
Subject:
Service Engine Soon Light on with DTC P0446 Set (Replace Canister)
Models:
2003 Chevrolet Silverado
2003 GMC Sierra
with 4.3L, 4.8L, 5.3L, 6.0L or 8.1 L Engine (VINs W, X, V, P, T, N, U, G - RPOs L35, LU3, LR4, LM4, LM7, LQ9, LQ4, L18)
Condition
Some customers may comment on the Service Engine Soon light being illuminated. Upon investigation, the technician will find a DTC P0446, EVAP system blocked or restricted vent path.
Cause
Variation in flow restriction through the EVAP canister may cause the new diagnostic to set the code.
Correction
Check the system operation using the current diagnostics for P0446.
If diagnostics lead you to replace the EVAP Canister or no concerns are found, then replace the EVAP canister and bracket. A new canister has been released with pelletized charcoal instead of powdered charcoal. This allows for a less restricted, more consistent flow through the canister.
Parts Information
Parts are currently available from GMSPO.
Warranty Information
For vehicles repaired under warranty, use the table.
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