P0456 on Your 2024 Silverado: Warranty Makes This Easy
Your 2024 Silverado (T1XX platform, refreshed) has triggered P0456—a very small EVAP leak at just 0.020 inches. Whether you're running the 2.7L turbo-four, 5.3L V8, 6.2L V8, or the 3.0L Duramax diesel, GM's EVAP system uses a traditional threaded gas cap and a vent valve solenoid near the spare tire. On a vehicle this new, warranty coverage makes this a no-cost repair.
Symptoms
- Steady check engine light
- P0456 stored in ECM
- No towing or performance issues
- Truck operates normally
Top Causes
- Gas Cap Seal (High Likelihood): GM uses traditional threaded gas caps. A loose cap or debris on the seal triggers P0456 instantly. $0 warranty (tighten) or $10–$15 new cap.
- Vent Valve Solenoid (High Likelihood): Located near the spare tire on the Silverado. GM's most common EVAP failure point. Well-documented in TSBs. $0 warranty repair.
- Purge Solenoid (Medium Likelihood): In the engine bay, controls vapor flow. Manufacturing variance on a new model. $0 warranty.
- EVAP Line Connection (Medium Likelihood): Factory assembly issue or worksite vibration. $0 warranty.
- Software Calibration (Low Likelihood): GM may issue ECM updates for EVAP detection. $0 warranty flash.
What to Do
- Remove and reseat the gas cap—listen for the click
- Schedule a warranty appointment at your Chevy dealer
- Let the dealer diagnose with GM's GDS2 tool
- Ask about TSBs for the 2024 Silverado EVAP system
Cost
- Under warranty: $0
- Bumper-to-bumper through 2027 (3yr/36k)
- Federal emissions through 2032 (8yr/80k)
Can I Tow?
Yes. P0456 has zero impact on the Silverado's towing capacity, payload, engine performance, or any mechanical system. Tow and haul normally.
Warranty
Your 2024 Silverado is fully covered under GM's 3yr/36k bumper-to-bumper through 2027. Federal emissions (8yr/80k) covers EVAP through 2032. Let the dealer handle everything at no cost.