DTC P0446: EVAP Control System - Vent Valve Control Circuit Malfunction: Condition
WARNING: This page is about a different car, the 2002 Suzuki XL-7. However, it is still accessible from the selected car via links, so may be relevant.
DTC P0446 is set when fuel tank pressure is lower than specification when ECM commands EVAP Canister Vent Valve (EVAP-CVV) off, (EVAP-CVV is open). MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles.