P0446 on Nissan
Evaporative Emission Control System Vent Control Circuit
P0446 on Nissan vehicles indicates evaporative emission control system vent control circuit. Au7o has documented this code across 2 Nissan models — most commonly on Frontier, Quest. This emissions code points to a problem in the evaporative emission (EVAP) system's vent control circuit, which manages the vent valve that lets the charcoal canister breathe and seals it during leak tests. The EVAP system captures fuel vapors from the tank to keep them out of the atmosphere, and the vent valve must open and close on command for the system to work and self-test. The code sets when the engine computer detects an electrical or performance fault with this vent valve or its circuit. It usually causes only a check engine light with no driveability change, but it does prevent proper EVAP leak monitoring. Typical repair costs on Nissan range from $100 to $1,500, depending on the specific model and root cause.
Common Causes of P0446
- •Faulty EVAP vent control valve (solenoid)
- •Wiring or connector fault in the vent valve circuit
- •Vent valve clogged with dirt, debris, or spider webs
- •Damaged or corroded vent valve connector
- •Blocked or pinched vent hose or filter
- •Faulty charcoal canister assembly
- •Faulty engine control module driver circuit
P0446 on Nissan by Model
Nissan Frontier(1 issue)
- EVAP Canister and Vent Control Valve Failure Triggering Check Engine Light2000-2004
The evaporative emissions system on these trucks commonly develops faults from a sticking vent control valve, saturated charcoal canister, cracked hoses, or rust/dirt intrusion near the rear-mounted canister. Owners frequently report persistent check-engine lights and failed emissions inspections even though the truck otherwise drives normally. Nissan published EVAP-related service bulletins for leak and vent valve diagnosis on Frontier/Xterra-era trucks.
Nissan Quest(1 issue)
- Rear A/C System Failure2011-2017
The Quest rear A/C system fails prematurely due to the rear evaporator developing leaks. The rear A/C then blows warm air while the front works normally. The rear expansion valve can also stick, preventing proper refrigerant flow. Repairing the rear A/C requires significant disassembly of interior panels.
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View P0446 across all makes →Frequently Asked Questions
What does P0446 mean on Nissan?▼
P0446 stands for "Evaporative Emission Control System Vent Control Circuit." This emissions code points to a problem in the evaporative emission (EVAP) system's vent control circuit, which manages the vent valve that lets the charcoal canister breathe and seals it during leak tests. The EVAP system captures fuel vapors from the tank to keep them out of the atmosphere, and the vent valve must open and close on command for the system to work and self-test. The code sets when the engine computer detects an electrical or performance fault with this vent valve or its circuit. It usually causes only a check engine light with no driveability change, but it does prevent proper EVAP leak monitoring. On Nissan specifically, this code is documented across 2 models.
What causes P0446 on Nissan vehicles?▼
Common causes on Nissan: Faulty EVAP vent control valve (solenoid), Wiring or connector fault in the vent valve circuit, Vent valve clogged with dirt, debris, or spider webs, Damaged or corroded vent valve connector, Blocked or pinched vent hose or filter. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0446 on a Nissan?▼
Repair costs on Nissan range from $100 to $1,500, depending on the specific model and root cause.
Which Nissan models have P0446 documented?▼
Au7o has documented P0446 on 2 Nissan models: Frontier, Quest.