Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Circuit Description
Vapor pressure sensor and Vacuum Switching Valve (VSV) for vapor pressure sensor are used to detect faults in EVAP system. DTC P0440 is set if EVAP system leak is detected or vapor pressure sensor malfunctions (detection of atmospheric pressure in fuel tank). Possible causes are:
- Hose between fuel tank and charcoal canister damaged.
- Fuel tank cap installed incorrectly.
- Fuel tank cap defective.
- Damaged, disconnected or blocked vacuum hose.
- Fuel tank damaged.
- Charcoal canister damaged.
- Open or short in vapor pressure sensor circuit.
- Faulty vapor pressure sensor.
- Fuel tank overfill check valve cracked or damaged.
- Faulty ECM.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.