The fault code P0446 in the 2004 Chevy Silverado means that the computer has detected an electrical issue within the EVAP system vent control. The ECM sends a signal to the vent control valve to purge the gas vapors from the charcoal canister and directs them to the engine. When the P0446 fault happens, they vapors arent being purged. This can happen because of something as simple as a loose or damaged gas cap, but there are other things You might need to look at. A defective vent control valve, a kinked or damaged fuel filler neck or bad fuel pump gasket are all potential causes. It is possible to get gas in the charcoal canister if You overfill the gas tank while the engine is running, this can clog it and will cause this code too.
Emma J
July 16, 2020
The 2004 Chevy silverado p0446 lists the evaporative emission control system vent control circuit malfunction. Code p0446 is established when the engine machine detects a malfunction or constraint in the vent control portion of the evaporative emission control device (evap).
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