P0446 on Toyota vehicles
EVAP Vent Control Circuit Fault — what it means on a Toyota, whether it's safe to drive, and the fixes by model and year.
P0446 on a Toyota means evap vent control circuit fault. Most vehicles stay drivable short-term, but diagnose it promptly. The most common cause is failed evap vent valve / vent solenoid (mechanical sticking) (typically $80–$350). Pick your Toyota model below for its known failure patterns, recalls, and TSBs.
What does P0446 mean on a Toyota?
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.
P0446 is a standardized OBD-II code, so its definition is the same on every Toyota. What differs by model and engine is which cause is most likely — pick your Toyota model below for a diagnosis tuned to its known failure patterns, recalls, and TSBs.
Is it safe to drive a Toyota with P0446?
In most cases a Toyota 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. Exact tolerance depends on the model and engine.
What causes P0446 on a Toyota?
| 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 |
Repair costs are typical US ranges and vary by Toyota model, model year, and labor rate. A diagnostic trouble code is a symptom, not a guaranteed failed part — confirm the root cause before replacing anything.
P0446 by Toyota model
Select your Toyota model and year for a P0446 diagnosis tuned to that vehicle's failure patterns, recalls, and TSBs.
Toyota RAV4
691 NHTSA owner complaints · 9 recalls on record across the years covered below.
Toyota Camry
842 NHTSA owner complaints · 6 recalls on record across the years covered below.
Toyota Corolla
721 NHTSA owner complaints · 8 recalls on record across the years covered below.
Toyota Tacoma
583 NHTSA owner complaints · 15 recalls on record across the years covered below.
Toyota 4Runner
170 NHTSA owner complaints · 16 recalls on record across the years covered below.
Toyota Highlander
650 NHTSA owner complaints · 11 recalls on record across the years covered below.
Toyota Sienna
393 NHTSA owner complaints · 22 recalls on record across the years covered below.
Complaint and recall counts are NHTSA totals for the model years covered on this site, not counts specific to P0446.
P0446 on other makes
Other codes on Toyota vehicles
P0446 on a Toyota: frequently asked questions
What does diagnostic trouble code P0446 mean on a Toyota?
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. P0446 is a standardized OBD-II code, so the definition is the same on every Toyota — which cause is most likely varies by model and engine.
What are the symptoms of P0446 on a Toyota?
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 Toyota?
Failed EVAP vent valve / vent solenoid (mechanical sticking) (most-common). Dirt, debris, or spider webs clogging the vent valve filter (common). Damaged wiring or connector at the vent valve (common). Failed PCM driver circuit for the vent valve (rare) (rare). Cracked or saturated EVAP charcoal canister (occasional)
Is it safe to drive a Toyota with P0446?
In most cases a Toyota stays drivable for short trips with P0446 active, but it should be diagnosed and repaired promptly — this is a low-severity code. Ignoring it can lead to further damage or a failed emissions test. Exact tolerance depends on the model and engine.