P0456 on Your 2024 3 Series: Precision Diagnosis
Your 2024 3 Series (G20 LCI) has flagged P0456—a very small EVAP leak. BMW uses a DMTL (Diagnosis Module Tank Leakage) pump instead of the simpler systems in other brands—it actively pressurizes the EVAP system for leak detection. The B48 2.0L turbo (330i) or B58 3.0L turbo (M340i) are unaffected. Fully covered under BMW's 4yr/50k warranty through 2028.
Clues
- Check engine light on
- P0456 stored
- No performance issues
- Gas cap may not be fully seated—BMW uses capless filler on some models
Suspects
- Fuel Filler Seal/Cap (High Likelihood): Debris in capless filler or loose cap. $0 warranty.
- DMTL Pump (High Likelihood): BMW's active leak detection module—common failure. $0 warranty.
- Purge Valve (Medium Likelihood): Manufacturing variance. $0 warranty.
- EVAP Line (Low Likelihood): Connection. $0 warranty.
- Software Update (Low Likelihood): DMTL calibration. $0 warranty.
What to Do
- Check fuel filler—clean any debris from capless filler opening
- If light persists, BMW dealer appointment—covered through 2028
- Free warranty repair via BMW ISTA diagnostics
Cost
- Under warranty: $0
- 4yr/50k through 2028
- Federal emissions through 2032
Can I Drive?
Yes. P0456 has zero impact on the turbo engine, xDrive, or any performance system.
Warranty
BMW's 4yr/50k through 2028. Federal emissions 8yr/80k through 2032. Fully covered.