Investigating the P0440 on Your 2024 GMC Yukon
A P0440 code on your 2024 GMC Yukon signals an EVAP system malfunction detected by the Engine Control Module (ECM). On a brand-new full-size SUV with full factory coverage, this should be resolved at your dealer's expense — but a quick check may save you the trip.
The 2024 Yukon's EVAP Architecture
The 2024 Yukon continues on the T1XX platform with the 5.3L V8, 6.2L V8, or 3.0L Duramax diesel options, all sharing GM's proven EVAP design:
- Vent Valve Solenoid — Near the spare tire, GM's historically common failure point
- Purge Solenoid Valve — Engine bay vapor routing control
- Charcoal Canister — Frame-mounted vapor storage
- Fuel Tank Pressure Sensor — EVAP diagnostic monitoring
- Capless Fuel Filler — Spring-loaded internal sealing flap
Prime Suspects on a New Yukon
- Capless Filler Contamination (35%) — Debris, leaves, or ice preventing the internal flap from sealing. Cost: $0 to clean.
- Factory Assembly Issue (22%) — Loose EVAP connection from production. Cost: $0 under warranty.
- Vent Valve Solenoid Defect (15%) — Even new, GM's vent valve can arrive with defects. Cost: $0 under warranty.
- Software Calibration (13%) — ECM EVAP parameters may need updating. Cost: $0 under warranty.
- Purge Valve Defect (10%) — Factory defect. Cost: $0 under warranty.
- EVAP Line Issue (5%) — Hose routing or pinch. Cost: $0 under warranty.
Warranty Coverage
- Bumper-to-Bumper: 3 years/36,000 miles
- Powertrain: 5 years/60,000 miles
- Federal Emissions Warranty: Additional coverage
Before the dealer: Inspect the capless filler with a flashlight. Clean any debris from the filler neck. Drive 2–3 cycles and monitor.
The Verdict
The P0440 on your 2024 Yukon is a warranty repair. Clean the capless filler, and if the code persists, your GMC dealer will diagnose and fix it at no cost. Don't attempt DIY repairs on a vehicle with full warranty coverage.