P0456 on Mazda vehicles A very small leak in the evaporative emissions system
P0456 is named on 18 Mazda model years (2016–2019): 36 manufacturer filings and 0 owner reports in NHTSA’s files, across CX-5, Mazda3, Mazda6, CX-3, CX-9.
Which Mazda model years name P0456
Source: NHTSA manufacturer communications and complaints| Model year | Filed under | Bulletins | Owner reports |
|---|---|---|---|
| 2017 Mazda Mazda3 | Engine | 3 | — |
| 2016 Mazda CX-5 | Engine | 3 | — |
| 2016 Mazda Mazda6 | Engine | 3 | — |
| 2018 Mazda CX-3 | Engine | 2 | — |
| 2018 Mazda CX-5 | Engine | 2 | — |
| 2018 Mazda CX-9 | Engine | 2 | — |
| 2018 Mazda Mazda3 | Engine | 2 | — |
| 2018 Mazda Mazda6 | Engine | 2 | — |
| 2017 Mazda CX-3 | Engine | 2 | — |
| 2017 Mazda CX-5 | Engine | 2 | — |
| 2017 Mazda CX-9 | Engine | 2 | — |
| 2017 Mazda Mazda6 | Engine | 2 | — |
| 2016 Mazda CX-3 | Engine | 2 | — |
| 2016 Mazda CX-9 | Engine | 2 | — |
| 2016 Mazda Mazda3 | Engine | 2 | — |
| 2019 Mazda CX-3 | Engine | 1 | — |
| 2019 Mazda CX-9 | Engine | 1 | — |
| 2019 Mazda Mazda3 | Engine | 1 | — |
A model year is listed because the code is named in its own record — a bulletin filed against it, or an owner’s complaint about it — not because every one of these vehicles sets it. Counts are documents in NHTSA’s files, not failure rates.
Mazda filings that name P0456
Source: NHTSA manufacturer communicationsBulletins and campaigns Mazda filed with NHTSA whose summary names P0456. Quote the document number at the service desk — it is a diagnosis the maker has already written down.
- 01-008-15-3045 Service bulletin2015-05-15 · Equipment — Other — Owners/Service/Other Manual
- SOME VEHICLES MAY EXHIBIT THE CHECK ENGINE LIGHT ON WITH DTC P0456 STORED IN THE PCM MEMORY. P0456: EVAP SYSTEM LEAK DETECTED (VERY SMALL LEAK) THE CONCERN IS MOST LIKELY THE RESULT OF THE CUSTOMER NOT GETTING THE FUEL CAP COMPLETELY CLOSED AFTER FUELING THE VEHICLE. THIS CAUSES A SMALL FUEL VAPOR LEAK AND TURNS DTC P0456 ON.
- 01-013-18-3478 Service bulletin2018-05-11 · Engine And Engine Cooling — Exhaust System
- Some vehicles may exhibit the check engine light on with DTC P0456 stored in the PCM memory. P0456: EVAP system leak detected (very small leak)The concern is most likely the result of the customer not getting the fuel cap completely closed after fuelingthe vehicle. This causes a small fuel vapor leak and turns DTC P0456 on.
- 01-005-19-3548 Service bulletin2019-01-10 · Engine And Engine Cooling
- Some vehicles may exhibit the check engine light on with DTC P0456 stored in the PCM memory. P0456: EVAP system leak detected (very small leak). The concern is most likely the result of the customer not getting the fuel cap completely closed after fueling the vehicle. This causes a small fuel vapor leak and turns DTC P0456 on.
- SA-030-18 Service bulletin2018-06-25 · Fuel System, Gasoline
- Some customer may complain about the CHECK ENGINE light ON while driving. When diagnosed, it is found that the PCM has stored DTC P0456 for evaporative gas leakage (extremely low). This may be caused by leakage detected from the catch tank unit (1) at the purge valve (2).
What P0456 means
Source: SAE J2012 / OBD-IIA very small leak in the evaporative emissions system.
A stored code names the test that failed, never the part that caused it. The record above is what Mazda and its owners have filed about it; the code’s page across every make has the whole file.
Common questions
Source: NHTSA files and the OBD-II standardIs P0456 a known problem on Mazda vehicles?
It is a documented one: NHTSA's files hold 36 manufacturer filings and 0 owner reports naming P0456 on 18 Mazda model years (2016–2019). Whether it is a problem on one particular car is a diagnosis, not a count — but a bulletin that names the code on your model year is the place to start.
Which Mazda models does P0456 appear on most?
2016 CX-5 (3 documents), 2017 Mazda3 (3 documents), 2016 Mazda6 (3 documents).
Does P0456 on a Mazda mean it is recalled?
No. Recalls are filed by campaign and matched by VIN; no recall is triggered by a scan tool. Check the VIN at nhtsa.gov/recalls, or open the model year's page here for the campaigns filed against it.