What does this code mean?
P0442 describes a small leak, P0455 a large leak and P0456 a very small leak. Check the correct fuel-cap seal where fitted, hoses, valves and the manufacturer's leak-test procedure. A loose cap is one possibility, not the only cause. Do not use compressed air or improvised flame tests around fuel vapour.
Sources and interpretation [1]
A code identifies a detected condition, not a part that must automatically be replaced.
Manufacturer communications
5Original wording in English
FORD
Reported code forms P0456
SOME 2016-2017 FOCUS RS VEHICLES EQUIPPED WITH A 2.3L GASOLINE TURBOCHARGED DIRECT INJECTION (GTDI) ENGINE AND BUILT ON OR BEFORE 10-DEC-2016 MAY EXHIBIT AN ILLUMINATED MIL WITH DTCS P0456, P1450 AND/OR P144A. THIS MAY…
FORD
Reported code forms P0456
Some 2012-2015 Focus vehicles may exhibit inaccurate fuel gauge indication and/or inaccurate distance to empty. The vehicle may also exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes…
FORD
Reported code forms P0456
FORD 2012-2014 FOCUS: CERTAIN VEHICLES MAY HAVE INCORRECT FUEL GAUGE INDICATION LAMP WITH DIAGNOSTIC CODES P0420, P1450, P0452,P0456, P0460 OR P2196. *LJ
FORD
Reported code forms P0456
FORD: VEHICLES MAY EXHIBIT A MALFUNCTION INDICATOR LIGHT (MIL) ON WITH DIAGNOSTIC TROUBLE CODE (DTC) P0456 (VERY SMALL EVAPORATIVE EMISSION SYSTEM LEAK DETECTED; VERY SMALL LEAK 0.020" (0.51 MM) DIAMETER). *PE
FORD, LINCOLN, MERCURY
Reported code forms P0456
MALFUNCTION INDICATOR LAMP (MIL) ILLUMINATION WITH DIAGNOSTIC TROUBLE CODES P0442, P0455, P0456, P0457, P1442 OR CHECK FUEL CAP LAMP ILLUMINATED WITH DIAGNOSTIC TROUBLE CODE P0457. *TT
Check vehicle applicability
12A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
Historical vehicle association; OBD-II compatibility is not established by this record.
| Make | Model | Model year |
|---|---|---|
| Ford | FOCUS | 2017 |
| Ford | FOCUS | 2016 |
| Ford | FOCUS | 2015 |
| Ford | FOCUS | 2014 |
| Ford | FOCUS | 2013 |
| Ford | FOCUS | 2012 |
| Ford | FOCUS | 2009 |
| Ford | FOCUS | 2008 |
| Ford | FOCUS | 2003 |
| Ford | FOCUS | 2002 |
| Ford | FOCUS | 2001 |
| Ford | FOCUS | 2000 |
Historical records · 1 · Historical vehicle association; OBD-II compatibility is not established by this record.
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Sources and interpretation
These explanations are editorial summaries of the linked manufacturer material. PDF page numbers count from the first file page. Original publications are in English; translations are reference aids. A cited edition is not a claim that it is the manufacturer's latest instruction.
- 2024–2025 MY OBD System Operation Summary for Gasoline Engines ↗
Ford Motor Company · PDF page(s) 13, 14 ·
Source check date · 2026-10-27
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.