P0303 on the 2016 Mazda Mazda3
The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.
Nobody has written a description of this code yet.
| 01-002-17 | 2021-01-25. Service bulletin. When the engine is started for the first time after parking the vehicle overnight in cold conditions (below 32 degrees Fahrenheit/0 degrees Celsious). Some vehicles may exhibit a rough idle and/or the check engine light on with any of the following DTC(s) stored in memory. *P0300 - Random misfire detected *P0301-Cylinder No.1 misfire detected *P0302 Cylinder No.2 misfire detected *P0303-Cylinder No.3 misfire detected *P0304 Cynlinder No.4 misfire Detected This may be caused by frozen water accumulated in the main silencer, restricting exhaust flow. Customers having this cocern should have their vehicle repaired using the ffollowifng repair procedure. |
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| 01-007-19-3541 | 2019-02-19. Service bulletin. When the engine is started for the first time after parking the vehicle overnight in cold conditions (below 32 degrees Fahrenheit / 0 degrees Celsius), some vehicles may exhibit a rough idle and/or the check engine light on with any of the following DTC(s) stored in memory. P0300 - Random misfire detected P0301 - Cylinder No. 1 misfire detected P0302 - Cylinder No. 2 misfire detected P0303 - Cylinder No. 3 misfire detected P0304 - Cylinder No.4 misfire detected. This may be caused by frozen water accumulated in the main silencer, restricting exhaust flow. |
| 01-006-18-3429 | 2018-04-23. Service bulletin. When the engine is started for the first time after parking the vehicle overnight in cold conditions (below 32 degrees Fahrenheit / 0 degrees Celsius), some vehicles may exhibit a rough idle and/or the check engine light on with any of the following DTC(s) stored in memory. P0300 - Random misfire detected P0301 - Cylinder No.1 misfire detected P0302 - Cylinder No.2 misfire detected P0303 - Cylinder No.3 misfire detected P0304 - Cylinder No.4 misfire detected. This may be caused by frozen water accumulated in the main silencer, restricting exhaust flow. |
| 01-004-17-3317a | 2017-10-21. Service bulletin. Some vehicles may experience an engine that runs rough and the check engine light on with DTCs P0201 and P0204 or P0202 and P0203. NOTE: Engine misfire related DTCs (P0301, P0302, P0303, P0304) are usually stored at the same time. P0201:00 : Fuel injector circuit/open cylinder No.1 P0202:00 : Fuel injector circuit/open cylinder No.2 P0203:00 : Fuel injector circuit/open cylinder No.3 P0204:00 : Fuel injector circuit/open cylinder No.4 This concern may be caused by an internal failure of the PCM (DENSO produced only). To correct the concern, the PCM internal failure has been eliminated. |
| 01-002-17-3299a | 2017-08-10. Service bulletin. When the engine is started for the first time after parking the vehicle overnight in cold conditions (below 32 degrees Fahrenheit / 0 degrees Celsius), some vehicles may exhibit a rough idle and/or the check engine light on with any of the following DTC(s) stored in memory.?P0300 - Random misfire detected ?P0301 - Cylinder No.1 misfire detected ?P0302 - Cylinder No.2 misfire detected ?P0303 - Cylinder No.3 misfire detected ?P0304 - Cylinder No.4 misfire detected This may be caused by frozen water accumulated in the main silencer, restricting exhaust flow. |
| 01-011-16-3139A | 2017-02-24. Service bulletin. WHEN THE ENGINE IS STARTED FOR THE FIRST TIME AFTER PARKING THE VEHICLE OVERNIGHT IN COLD CONDITIONS (BELOW 32 DEGREES FAHRENHEIT / 0 DEGREES CELSIUS), SOME VEHICLES MAY EXHIBIT A ROUGH IDLE AND/OR THE CHECK ENGINE LIGHT ON WITH ANY OF THE FOLLOWING DTC(S) STORED IN MEMORY.•P0300 - RANDOM MISFIRE DETECTED•P0301 - CYLINDER NO.1 MISFIRE DETECTED•P0302 - CYLINDER NO.2 MISFIRE DETECTED •P0303 - CYLINDER NO.3 MISFIRE DETECTED •P0304 - CYLINDER NO.4 MISFIRE DETECTED THIS MAY BE CAUSED BY FROZEN WATER ACCUMULATED IN THE MAIN SILENCER, RESTRICTING EXHAUST FLOW. |
| 01-014-16-3208 | 2017-02-24. Service bulletin. SOME VEHICLES MAY EXPERIENCE A LACK OF ENGINE POWER/ROUGH IDLING AND THE CHECK ENGINE LIGHT ON WITH ONE OR MORE OF THE MISFIRE RELATED DTCS OF P0300:00, P0301:00, P0302:00, P0303:00 AND P0304:00. THIS CONCERN MAY BE CAUSED BY AN INTERNAL FAILURE OF THE IGNITION COIL(S) DUE TO A HIGH DIFFERENCE BETWEEN COLD AND WARM AMBIENT TEMPERATURES. THE PRODUCTION METHOD OF THE IGNITION COIL HAS BEEN CHANGED TO ELIMINATE THIS CONCERN. |
| 01-017-16-3242 | 2017-02-23. Service bulletin. SOME VEHICLES MAY EXPERIENCE AN ENGINE THAT RUNS ROUGH AND THE CHECK ENGINE LIGHT ON WITH DTCS P0201 AND P0204 OR P0202 AND P0203.NOTE:ENGINE MISFIRE RELATED DTCS (P0301, P0302, P0303, P0304) ARE USUALLY STORED AT THE SAME TIME.P0201:00: FUEL INJECTOR CIRCUIT/OPEN CYLINDER NO.1P0202:00: FUEL INJECTOR CIRCUIT/OPEN CYLINDER NO.2P0203:00: FUEL INJECTOR CIRCUIT/OPEN CYLINDER NO.3P0204:00: FUEL INJECTOR CIRCUIT/OPEN CYLINDER NO.4THIS CONCERN MAY BE CAUSED BY AN INTERNAL FAILURE OF THE PCM (DENSO PRODUCED ONLY). TO CORRECT THE CONCERN, THE PCM INTERNAL FAILURE HAS BEEN ELIMINATED. |
| 01-011-16-3139A | 2017-02-17. Service bulletin. WHEN THE ENGINE IS STARTED FOR THE FIRST TIME AFTER PARKING THE VEHICLE OVERNIGHT IN COLD CONDITIONS (BELOW 32 DEGREES FAHRENHEIT / 0 DEGREES CELSIUS), SOME VEHICLES MAY EXHIBIT A ROUGH IDLE AND/OR THE CHECK ENGINE LIGHT ON WITH ANY OF THE FOLLOWING DTC(S) STORED IN MEMORY.•P0300 - RANDOM MISFIRE DETECTED•P0301 - CYLINDER NO.1 MISFIRE DETECTED•P0302 - CYLINDER NO.2 MISFIRE DETECTED •P0303 - CYLINDER NO.3 MISFIRE DETECTED •P0304 - CYLINDER NO.4 MISFIRE DETECTED THIS MAY BE CAUSED BY FROZEN WATER ACCUMULATED IN THE MAIN SILENCER, RESTRICTING EXHAUST FLOW. |
| 01-014-16-3208 | 2017-02-16. Service bulletin. SOME VEHICLES MAY EXPERIENCE A LACK OF ENGINE POWER/ROUGH IDLING AND THE CHECK ENGINE LIGHT ON WITH ONE OR MORE OF THE MISFIRE RELATED DTCS OF P0300:00, P0301:00, P0302:00, P0303:00 AND P0304:00. THIS CONCERN MAY BE CAUSED BY AN INTERNAL FAILURE OF THE IGNITION COIL(S) DUE TO A HIGH DIFFERENCE BETWEEN COLD AND WARM AMBIENT TEMPERATURES. THE PRODUCTION METHOD OF THE IGNITION COIL HAS BEEN CHANGED TO ELIMINATE THIS CONCERN. |
12 on file from NHTSA, as of 2026-10-19. See them in the bulletin list. A bulletin lists model years: read the document for which vehicles it concerns.