What does code P0446 mean on a GMC and is it safe to drive?
P0446: Evaporative Emission System Vent Control Circuit. Here's what it means on your GMC, what usually causes it, what repairs typically cost, and how safe it is to keep driving.
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What this code means
The PCM has detected a problem with the EVAP vent control circuit, often caused by a stuck or failed vent valve.
Common causes for your GMC
- Failed EVAP vent solenoid
- Corroded wiring or connector at vent valve
- Blocked vent due to dust, rust, or spider webs
Symptoms
- Check Engine Light
- Possible difficulty filling fuel tank (nozzle keeps clicking off)
Typical fixes
- Replace EVAP vent valve/solenoid
- Clean or clear vent and charcoal canister area
- Repair wiring
Repair cost range
For a GMC, repairs for P0446 often fall between $150 and $450, depending on the cause and whether you use OEM or aftermarket parts. Labor rates vary by location.
Known issues on GMC
GMC P0446 vent solenoid fault follows the same pattern as Chevrolet trucks. On Sierra and Yukon, corrosion at the vent solenoid connector from road salt and underbody moisture is a common cause—clean or replace the connector before condemning the solenoid.
Most commonly affected models
Sierra 1999–2007Yukon 2000–2006Acadia 2007–2016