P0455: Système EVAP — fuite importante détectée
Système EVAP — fuite importante détectée : EVAP monitor failed to pull or hold vacuum in the fuel tank vapor system, indicating a large leak or missing cap.
| Trouble Code (DTC) | P0455 |
|---|---|
| Official SAE Definition | Système EVAP — fuite importante détectée |
| Vehicle Subsystem | powertrain |
| Driving Severity | LOW |
Observable Symptoms
- Check Engine Light on
- Faint fuel vapor odor near rear wheel well
- No immediate drivability loss
Most Probable Root Causes
- Loose, damaged, or missing fuel filler cap
- Stuck-open EVAP canister vent valve or purge valve
- Cracked charcoal canister or vapor hose
Step-by-Step Diagnostic Procedure
- Inspect fuel cap O-ring seal and tighten until click
- Command EVAP purge and vent valves via scan tool and perform EVAP smoke test