P0446
Low SeverityEVAP Vent Control Circuit
EVAP System
P0446 — Instant Answer
EVAP Vent Control Circuit
Severity: LOW SEVERITY
Meaning: Fault in the EVAP vent valve circuit. The vent valve allows the EVAP system to breathe.
Safe to drive? Usually yes with caution, but confirm root cause before long trips.
Estimated repair cost: $20 - $60
Most common causes:
- 1. Failed vent valve (35-45% of cases)
- 2. Blocked vent filter (10-25% of cases)
- 3. Wiring issue (10-25% of cases)
Symptoms
- ⚠️Check engine light
- ⚠️Possible fuel smell
- ⚠️Failed emissions
Related Symptoms
Common Causes
How to Diagnose P0446
- 1Check vent valve connector
- 2Test vent valve with 12V
- 3Inspect vent filter for blockage
- 4Replace valve
OEM Procedures for P0446
P0446 affects the Charcoal Canister. Found 2 OEM service manual procedures.
Charcoal Canister - Replacement (ES300)
Charcoal Canister - Replacement (ES300)
Charcoal Canister - Replacement (ES300)
Charcoal Canister - Replacement (ES300)
Charcoal Canister - Replacement (ES300)
Charcoal Canister - Replacement (ES300)
Charcoal Canister - Replacement (ES300)
Charcoal Canister - Replacement (ES300)
OEM Diagnostic Flowchart
Scroll to load technician if/then branches.
Read live data and freeze frame for P0446 to pinpoint the cause before buying parts.
TopScan
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DIYers who want phone-based scanning
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ArtiLink600
$99
DIYers working on ABS/airbag systems
View on TOPDONGot a repair estimate for P0446? Check if the quote is fair before ordering parts.
Parts & Tools for This Job
Common parts shoppers buy for P0446 EVAP Vent Control Circuit.
Oxygen Sensor
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Catalytic Converter
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EVAP Purge Valve
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Gas Cap
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Turn This Into a Confident Next Step
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OBD2 scanner
Read codes and freeze-frame data before you guess at the fault.
Most diagnostic jobs start with a scan tool and a verified code path.
Check SpecificationsBattery tester
Check cranking and charging health before replacing expensive parts.
A weak battery can mimic alternator or starter problems.
Check SpecificationsMultimeter kit
Confirm voltage, continuity, and sensor power with one simple kit.
A meter is the cheapest way to rule out a bad circuit fast.
Check SpecificationsRelated Resources
Repair guides, symptom pages, and wiring diagrams related to P0446.
OEM Manual Evidence
Browse →A L L Diagnostic Trouble Codes ( DTC ) — 2013 Buick Enclave AWD V6-3.6L Service Manual ~ LEMON Manuals LEMON Manuals: Repair Knowledge Reim...
A L L Diagnostic Trouble Codes ( DTC ) — 2013 Buick Enclave FWD V6-3.6L Service Manual ~ LEMON Manuals LEMON Manuals: Repair Knowledge Reim...
A L L Diagnostic Trouble Codes ( DTC ) — 2013 Buick LaCrosse AWD V6-3.6L Service Manual ~ LEMON Manuals LEMON Manuals: Repair Knowledge Rei...
A L L Diagnostic Trouble Codes ( DTC ) — 2013 Buick LaCrosse FWD L4-2.4L Service Manual ~ LEMON Manuals LEMON Manuals: Repair Knowledge Rei...
Related Symptoms
Browse →Exact Vehicle Hubs
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Open the exact vehicle hub grounded by OEM manual evidence related to P0446.
Open the exact vehicle hub grounded by OEM manual evidence related to P0446.
Open the exact vehicle hub grounded by OEM manual evidence related to P0446.
Related Codes
Frequently Asked Questions
- Where is the EVAP vent valve?
- Usually near the charcoal canister, often under the vehicle near the fuel tank area.
- Can spider webs block the vent valve?
- Yes — this is surprisingly common. Spiders build webs in the vent, blocking airflow and triggering P0446.
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Author & Review
Published by AllOEMManuals, founded by Lyndon Bedford, an automotive technician with 20 years of experience. He owned and operated a mechanic shop in Hurst, Texas from 2014 to 2022 and continues hands-on repair work.
Content may combine manual references, general repair templates, and AI-assisted drafting. Confirm the source, vehicle configuration, and applicability before working. Report corrections through our contact page.
Last updated: 2026-10-29