Decoding the P0440 on Your 2024 Lexus RX
A P0440 code on your 2024 Lexus RX — the second year of the completely redesigned fifth generation — means the ECM has detected an EVAP system malfunction. Built on Toyota's TNGA-K platform with your choice of the RX 350 (2.4L turbo) or RX 350h/RX 500h (hybrid), this is a warranty-covered issue.
The 2024 RX EVAP System
The redesigned RX uses Toyota/Lexus' modern EVAP design:
- Purge VSV — Vacuum Switching Valve controlling vapor flow from canister to intake
- Canister Close Valve (CCV) — Seals the canister for system integrity testing
- Charcoal Canister — Activated carbon vapor storage
- Vapor Pressure Sensor — In-tank pressure monitoring
- Fuel Filler System — Cap or capless depending on market/trim
Most Likely Causes
- Fuel Filler Issue (35%) — Gas cap or capless filler not sealing. Cost: $0.
- Factory Assembly Issue (22%) — EVAP connection not fully seated. Cost: $0 under warranty.
- Purge VSV Defect (15%) — Factory defect in the vacuum switching valve. Cost: $0 under warranty.
- Software Calibration (12%) — ECM EVAP monitoring refinement. Cost: $0 under warranty.
- CCV Issue (10%) — Canister close valve not sealing. Cost: $0 under warranty.
- EVAP Hose Routing (6%) — Connection or routing. Cost: $0 under warranty.
Lexus Warranty Coverage
- Basic Warranty: 4 years/50,000 miles
- Powertrain: 6 years/70,000 miles
- Federal Emissions: Additional coverage
Check the fuel filler first. If the code persists, your Lexus dealer will handle the rest at no cost.
The Verdict
The P0440 on your 2024 RX is a warranty repair. Lexus' 4-year/50,000-mile coverage is among the best in the industry. Check the filler, then schedule a dealer appointment. Toyota/Lexus EVAP systems are exceptionally reliable — this is almost certainly a one-time fix.