P0446 on a 2022 GMC Sierra 1500
EVAP Vent Control Circuit Fault
P0446 on a 2022 GMC Sierra 1500 indicates evap vent control circuit fault. It usually stays drivable short-term but should be diagnosed promptly. The most common cause is failed evap vent valve / vent solenoid (mechanical sticking) (typically $80–$350). Confirm the root cause before replacing parts.
What does P0446 mean on a 2022 GMC Sierra 1500?
P0446 is set when the engine control module detects that the EVAP vent valve circuit is not behaving as commanded. The vent valve is the normally-open solenoid that lets the charcoal canister breathe — and closes during the EVAP leak test to seal the system. P0446 typically means the vent valve is stuck (mechanically or electrically) so that the system can never seal properly for the leak test.
This guide covers P0446 across the 2020-2024 GMC Sierra 1500 generation — the symptoms, causes, and diagnostic steps below apply to every model year from 2020 through 2024.
Is it safe to drive a 2022 GMC Sierra 1500 with P0446?
In most cases a 2022 GMC Sierra 1500 stays drivable for short trips with P0446 active, but diagnose and repair it promptly. This is a low-severity code — ignoring it can lead to further damage or a failed emissions test.
What are the symptoms of P0446 on a 2022 GMC Sierra 1500?
- Check Engine Light is illuminated
- Difficulty filling the fuel tank (pump clicks off repeatedly)
- No other drivability problems
- Vehicle will fail emissions / smog testing
- Sometimes accompanied by P0455 (large leak) on the same scan
What causes P0446 on a 2022 GMC Sierra 1500?
| Cause | Likelihood | Estimated repair (USD) |
|---|---|---|
| Failed EVAP vent valve / vent solenoid (mechanical sticking) | Most common | $80–$350 |
| Dirt, debris, or spider webs clogging the vent valve filter Common on trucks and SUVs with the canister mounted under the vehicle. | Common | $20–$100 |
| Damaged wiring or connector at the vent valve | Common | $50–$250 |
| Failed PCM driver circuit for the vent valve (rare) | Rare | $400–$1,500 |
| Cracked or saturated EVAP charcoal canister | Occasional | $200–$600 |
How to diagnose this on a 2022 GMC Sierra 1500
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Locate the vent valve on this vehicle
The vent valve is mounted on or next to the charcoal canister. On most modern trucks and SUVs that is behind the rear bumper or near the fuel tank. On many cars it sits in the engine compartment. Consult the service manual for the exact location.
Tools: Vehicle-specific service information
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Test the vent valve electrically
Disconnect the valve connector. With the key on, check for battery voltage on the power side. Apply 12 V across the solenoid terminals directly — you should hear and feel it click. A solenoid that does not click is dead and needs replacement.
Tools: Multimeter, Test leads / jumper wires
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Test the vent valve mechanically
Disconnect the hose at the vent valve. Connect a hand vacuum pump. With the solenoid de-energized, the valve should let air flow freely (no vacuum holds). With 12 V applied, the valve should hold vacuum. A valve that holds vacuum at rest, or that leaks vacuum when commanded closed, is the problem.
Tools: Hand vacuum pump, 12 V test source
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Inspect for contamination
Trucks and SUVs frequently get spider webs, mud, or sand inside the vent valve filter on the canister side. Some vehicles have a dust filter that is replaceable; others integrate it into the valve assembly. Clean or replace as needed.
Tools: Compressed air, Replacement filter (if applicable)
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Confirm the canister itself is intact
With the vent valve removed, look into the canister port for cracked plastic, saturated charcoal (will smell strongly of fuel), or debris. A failed canister will cause repeated P0446 set events even after the vent valve is replaced.
Tools: Flashlight
NHTSA complaints & recalls for the 2022 GMC Sierra 1500
Owner-reported safety complaints and official recalls filed with the U.S. National Highway Traffic Safety Administration for the 2022 GMC Sierra 1500. Use these to gauge how common a problem is on your specific vehicle before you start chasing GMC Sierra 1500 diagnostics.
- ENGINE 207
- POWER TRAIN 92
- STRUCTURE 90
- ELECTRICAL SYSTEM 75
- UNKNOWN OR OTHER 70
6 active recalls
- EXTERIOR LIGHTING:BRAKE LIGHTS Jun 2022
General Motors (GM) has decided that certain 2022 model year Chevrolet Silverado, and GMC Sierra vehicles equipped with an accessory sport bar. The accessory sport bar contains a high-mounted brake light that may not function. In addition, it may block the vehicle's existing hi…
NHTSA campaign 22V463000 - EXTERIOR LIGHTING:LIGHTING CONTROL MODULE:SOFTWARE Dec 2022
General Motors, LLC (GM) is recalling certain 2020-2023 Cadillac CT4 and CT5; 2021-2023 Buick Envision; and 2022-2023 Cadillac Escalade and Escalade ESV, Chevrolet Silverado 1500, Suburban, Tahoe, GMC Sierra 1500, Yukon, and Yukon XL vehicles. The daytime running lights (DRLs) m…
NHTSA campaign 22V903000 - POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE:SOFTWARE Oct 2024
General Motors, LLC (GM) is recalling certain 2020-2022 Chevrolet Silverado 1500, 2500, 3500, GMC Sierra 1500, 2500, 3500, 2021 Cadillac Escalade, Escalade ESV, Chevrolet Tahoe, Suburban, GMC Yukon, and Yukon XL vehicles equipped with diesel engines. The transmission control val…
NHTSA campaign 24V797000 - STRUCTURE:BODY:BUMPERS:ACTIVE SHUTTERS/GRILL Feb 2025
General Motors, LLC (GM) is recalling certain 2022 GMC Sierra 1500 vehicles equipped with chrome front grille deflectors. The attachments that hold the front grille deflectors in place may fracture, resulting in grille detachment.…
NHTSA campaign 25V060000
How do I fix P0446 on a 2022 GMC Sierra 1500?
- Replace the EVAP vent valve / vent solenoid
- Clean the vent valve filter and inspection port
- Repair damaged wiring or connector at the vent valve
- Replace the charcoal canister assembly
About the 2020-2024 GMC Sierra 1500
The 2020-2024 GMC Sierra 1500 was commonly sold with the following powertrains: 5.3L V8, 6.2L V8, 2.7L Turbo I4, 3.0L Duramax I6 Diesel. Common trims include Pro, SLE, Elevation, SLT, AT4, Denali.
Why the gas pump clicks off with P0446
The vent valve is what allows the fuel tank to “breathe” during refueling. If the valve is stuck closed, displaced air cannot escape as fuel goes in — pressure builds, fuel splashes back into the filler neck, and the pump nozzle’s auto-shutoff triggers prematurely. If you have to “trickle fill” your tank to get gas in, P0446 (or a related vent code) is the most likely cause.
When P0446 sets with P0455
If P0446 (vent control) sets alongside P0455 (large leak), the root cause is usually one part — the vent valve is stuck open, so the system can never seal for the leak test, which triggers both codes. Replace the vent valve and clear codes; if P0455 returns alone the next monitor run, do a separate small-leak diagnosis.
Trucks and SUVs vs. cars
Under-vehicle mounted vent valves (most trucks, SUVs, and minivans) fail more often than engine-bay mounted ones. They live in a worse environment — road spray, salt, mud, debris. On vehicles with chronic P0446, an upgraded “all-terrain” vent valve or a relocation kit is sometimes worth considering after the second failure.