DTC P0446 - EVAP SYSTEM VENT VALVE PERFORMANCE GMC Envoy I

Note. For circuit reference, see WIRING DIAGRAMS - 4.3L article.

Circuit Description

Evaporative (EVAP) emission system includes following components: fuel tank, EVAP vent solenoid, fuel tank pressure sensor, fuel pipes and hoses, vapor lines, fuel cap, EVAP emission canister, purge lines, and EVAP purge solenoid.

Conditions for setting DTC are

1. No ECT, HO2S, IAT, MAP, TP or VSS sensor DTCs set.
2. DTC P0125 not active.
3. ECT and IAT 39-86°F (4-30°C).
4. Start-up IAT not greater than 14.9°F (8.3°C) than start-up ECT.
5. BARO greater than 72.5 kPa.
6. Excess vacuum present in EVAP system.