P0440 Toyota Highlander
EVAP System Malfunction · Powertrain Code · Low · Repair: Easy
What is P0440?
General EVAP (evaporative emission control) system malfunction. The system that prevents fuel vapors from escaping has detected a fault.
When the Toyota Highlander triggers code P0440 (evap system malfunction), it typically points to an issue in the powertrain system. Below you'll find the most common causes, symptoms, and repair options specific to the Toyota Highlander.
This repair is rated easy, meaning basic tools, no lift needed.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your Toyota Highlander.
Common Causes on Toyota Highlander
- EVAP system general malfunction — loose or worn gas cap is most common
- Cracked EVAP charcoal canister (common on Toyota trucks from road debris)
- Failed EVAP canister purge valve or vent valve
- Cracked or disconnected EVAP vapor hose
Symptoms
- Check Engine Light on
- Faint fuel odor near the vehicle
- No driveability symptoms
- Failed emissions test
Notes for Toyota Highlander
Toyota EVAP systems are sensitive — always check the gas cap first, as a loose cap causes 60%+ of P0440 codes on Toyota vehicles.