P0440
P0440 is the OBD-II diagnostic trouble code for Evaporative Emission Control System Malfunction. It indicates that the engine control module detected a fault within the EVAP system, which is responsible for capturing fuel vapors from the fuel system and routing them for combustion rather than releasing them to the atmosphere. The fault is broad and may arise from a minor issue or a more significant leak or component failure. When triggered, the vehicle’s check engine light typically comes on and the vehicle may fail an emissions test.
The EVAP system includes components such as the fuel tank, charcoal canister, purge valve, vent valve, associated
Common symptoms include a illuminated check engine light and, in some cases, a noticeable fuel odor or
Diagnosis typically begins with a scan for codes and a visual inspection of the gas cap and