P0304 · Communications du constructeur

JEEP · 2026-06-04

Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set one of the following Diagnostic Trouble Codes (DTCs): ● P1CEA - Boost Side Evap Purge System Performance. ● P0300-00 - Random/Multiple Cylinder Misfire Detected ● P0301-00 - Cylinder 1 Misfire ● P0302-00 - Cylinder 2 Misfire ● P0303-00 - Cylinder 3 Misfire ● P0304-00 - Cylinder 4 Misfire Customers may also experience one or more of the following: ● Engine RPM fluctuations at low vehicle speeds after extended idling. ● An ignition-off draw or battery drain condition. ● Sluggish engine performance and misfires. ● Engine knocking when the accelerator is pressed hard or quickly This bulletin involves inspecting and possibly reprogramming the…

MERCEDES-BENZ · 2026-06-03

Complaint Check engine light activated. Fault codes related to misfire on multiple cylinders stored. Possible fault codes listed below: P030004 - Combustion misfiring has been detected. There is an internal fault. P030100 - Combustion misfiring of cylinder 1 has been detected P030200 - Combustion misfiring of cylinder 2 has been detected P030300 - Combustion misfiring of cylinder 3 has been detected P030400 - Combustion misfiring of cylinder 4 has been detected P030500 - Combustion misfiring of cylinder 5 has been detected P030600 - Combustion misfiring of cylinder 6 has been detected P031600 - Combustion misfires were detected at engine start. Cause Under analysis Remedy Note: If the vehicle has a single cylinder misfiring or a constant misfire, diagnose the cause of this separately.…

FORD, LINCOLN · 2026-05-28

Some of the vehicles listed in the Model statement above may exhibit all of the following conditions: * Engine misfire condition * Illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) P0301, P0302, P0303, and/or P0304 stored in the powertrain control module (PCM)

RAM · 2026-04-30

Flash: Ignition System Control Module (ISCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P2C30-00 - Ignition Coil Primary Circuit Fuse A. ● P2C31-00 - Ignition Coil Primary Circuit Fuse B. ● P0300-00 - Multiple Cylinder Misfire. ● P0301-00 - Cylinder 1 Misfire Detected. ● P0302-00 - Cylinder 2 Misfire Detected. ● P0303-00 - Cylinder 3 Misfire Detected. ● P0304-00 - Cylinder 4 Misfire Detected. ● P0305-00 - Cylinder 5 Misfire. ● P0306-00 - Cylinder 6 Misfire. ● P0420-00 - Catalyst System Efficiency Below Threshold Bank 1. ● P0430-00 - Catalyst System Efficiency Below Threshold Bank 2. Customers may also comment on the following: ● Engine hesitates/misfires…

JEEP · 2026-04-18

Flash: Powertrain Control Module (PCM) Updates **Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs):** ● **P0300 - Multiple Cylinder Misfire - In Active or Stored status set during cold start catalyst heating. ● P0301 - Cylinder 1 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0302 - Cylinder 2 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0303 - Cylinder 3 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0304 - Cylinder 4 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0305 - Cylinder 5 Misfire - In Active or Stored status set during…

JEEP · 2026-04-18

Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0300 - Multiple Cylinder Misfire - In Active or Stored status set during cold start catalyst heating. ● P0301 - Cylinder 1 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0302 - Cylinder 2 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0303 - Cylinder 3 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0304 - Cylinder 4 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0305 - Cylinder 5 Misfire - In Active or Stored status set during cold…

JEEP · 2026-04-18

Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● **P0300 - Multiple Cylinder Misfire - In Active or Stored status set during cold start catalyst heating. ● P0301 - Cylinder 1 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0302 - Cylinder 2 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0303 - Cylinder 3 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0304 - Cylinder 4 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0305 - Cylinder 5 Misfire - In Active or Stored status set during cold…

JEEP · 2026-04-17

Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0300 - Multiple Cylinder Misfire (Active or Stored status set during cold start catalyst heating). ● P0301 - Cylinder 1 Misfire (Active or Stored status set during cold start catalyst heating). ● P0302 - Cylinder 2 Misfire (Active or Stored status set during cold start catalyst heating). ● P0303 - Cylinder 3 Misfire (Active or Stored status set during cold start catalyst heating). ● P0304 - Cylinder 4 Misfire (Active or Stored status set during cold start catalyst heating). ● P0305-00 - Cylinder 5 Misfire (Active or Stored status set during cold start catalyst…

JEEP · 2026-04-17

Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0300 - Multiple Cylinder Misfire (Active or Stored status set during cold start catalyst heating). ● P0301 - Cylinder 1 Misfire (Active or Stored status set during cold start catalyst heating). ● P0302 - Cylinder 2 Misfire (Active or Stored status set during cold start catalyst heating). ● P0303 - Cylinder 3 Misfire (Active or Stored status set during cold start catalyst heating). ● P0304 - Cylinder 4 Misfire (Active or Stored status set during cold start catalyst heating). ● P0305-00 - Cylinder 5 Misfire (Active or Stored status set during cold start catalyst…

JEEP · 2026-04-17

Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● **P0301 - Cylinder 1 Misfire (Active or Stored status set during cold start catalyst heating). ● P0302 - Cylinder 2 Misfire (Active or Stored status set during cold start catalyst heating). ● P0303 - Cylinder 3 Misfire (Active or Stored status set during cold start catalyst heating). ● P0304 - Cylinder 4 Misfire (Active or Stored status set during cold start catalyst heating). ● P0305-00 - Cylinder 5 Misfire (Active or Stored status set during cold start catalyst heating). ● P0306-00 - Cylinder 6 Misfire (Active or Stored status set during cold start catalyst…

JEEP · 2026-04-16

Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● **P0300 - Multiple Cylinder Misfire (Active or Stored status set during cold start catalyst heating). ● P0301 - Cylinder 1 Misfire (Active or Stored status set during cold start catalyst heating). ● P0302 - Cylinder 2 Misfire (Active or Stored status set during cold start catalyst heating). ● P0303 - Cylinder 3 Misfire (Active or Stored status set during cold start catalyst heating). ● P0304 - Cylinder 4 Misfire (Active or Stored status set during cold start catalyst heating). ● P0305-00 - Cylinder 5 Misfire (Active or Stored status set during cold start catalyst…

JEEP · 2026-04-16

Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● **P0300 - Multiple Cylinder Misfire (Active or Stored status set during cold start catalyst heating). ● P0301 - Cylinder 1 Misfire (Active or Stored status set during cold start catalyst heating). ● P0302 - Cylinder 2 Misfire (Active or Stored status set during cold start catalyst heating). ● P0303 - Cylinder 3 Misfire (Active or Stored status set during cold start catalyst heating). ● P0304 - Cylinder 4 Misfire (Active or Stored status set during cold start catalyst heating). ● P0305-00 - Cylinder 5 Misfire (Active or Stored status set during cold start catalyst…

JEEP · 2026-04-16

Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● **P0300 - Multiple Cylinder Misfire (Active or Stored status set during cold start catalyst heating). ● P0301 - Cylinder 1 Misfire (Active or Stored status set during cold start catalyst heating). ● P0302 - Cylinder 2 Misfire (Active or Stored status set during cold start catalyst heating). ● P0303 - Cylinder 3 Misfire (Active or Stored status set during cold start catalyst heating). ● P0304 - Cylinder 4 Misfire (Active or Stored status set during cold start catalyst heating). ● P0305-00 - Cylinder 5 Misfire (Active or Stored status set during cold start catalyst…

JEEP · 2026-03-25

Flash: Ignition System Control Module (ISCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P2C30-00 - Ignition Coil Primary Circuit Fuse A. ● P2C31-00 - Ignition Coil Primary Circuit Fuse B. ● P0300-00 - Multiple Cylinder Misfire. ● P0301-00 - Cylinder 1 Misfire Detected. ● P0302-00 - Cylinder 2 Misfire Detected. ● P0303-00 - Cylinder 3 Misfire Detected. ● P0304-00 - Cylinder 4 Misfire Detected. ● P0305-00 - Cylinder 5 Misfire Detected. ● P0306-00 - Cylinder 6 Misfire Detected. ● P0420-00 - Catalyst System Efficiency Below Threshold Bank 1. ● P0430-00 - Catalyst System Efficiency Below Threshold Bank 2. Customers may also comment on the following: ●…

DODGE · 2026-03-21

Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0300-00 - Multiple Cylinder Misfire - in Active or Stored status set during engine warm up period. ● P0301-00 - Cylinder 1 Misfire - in Active or Stored status set during engine warm up period. ● P0302-00 - Cylinder 2 Misfire - in Active or Stored status set during engine warm up period. ● P0303-00 - Cylinder 3 Misfire - in Active or Stored status set during engine warm up period. ● P0304-00 - Cylinder 4 Misfire -in Active or Stored status set during engine warm up period. ● P0305-00 - Cylinder 5 Misfire - in Active or Stored status set during engine warm up…

JEEP · 2026-03-13

Not applicable to vehicles built for US market. Fuel Injector Leak Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● **P1336-00 - Multiple Cylinder Misfire. ● P1337-00 - Cylinder 1 Misfire. ● P1338-00 - Cylinder 2 Misfire. ● P1339-00 - Cylinder 3 Misfire. ● P1340-00 - Cylinder 4 Misfire.** ● P0300-00 - Multiple Cylinder Misfire. ● P0301-00 - Cylinder 1 Misfire. ● P0302-00 - Cylinder 2 Misfire. ● P0303-00 - Cylinder 3 Misfire. ● P0304-00 - Cylinder 4 Misfire. Customers may also comment on one or more of the following: ● Unstable idle. ● Abnormal engine noise. , Diagnostic section, Repair Procedure, additional Claims Data Note, Special Tool and Reading Defects…

DODGE · 2026-02-28

Flash: Powertrain Control Module (PCM) Updates Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation SYMPTOM: the technician must find one or more of the following Diagnostic Trouble Codes (DTCs) have been set: ● P0300 - Multiple Cylinder Misfire. ● P0301 - Cylinder 1 Misfire. ● P0302 - Cylinder 2 Misfire. ● P0303 - Cylinder 3 Misfire. ● P0304 - Cylinder 4 Misfire. ● P0305 - Cylinder 5 Misfire. ● P0306 - Cylinder 6 Misfire. ● P0307 - Cylinder 7 Misfire. ● P0308 - Cylinder 8 Misfire. ● P0420 - Catalyst System Efficiency Below Threshold Bank 1. ● P0430 - Catalyst System Efficiency Below Threshold Bank 2. Customers may comment on or experience the following: ● A rough idle condition. This bulletin involves reprogramming the PCM with the latest…

DODGE · 2026-02-27

Flash: Powertrain Control Module (PCM) Updates Customers may experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle may SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0300-00 - Multiple Cylinder Misfire - in Active or Stored status set during cold start catalyst heating. ● P0301-00 - Cylinder 1 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0302-00 - Cylinder 2 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0303-00 - Cylinder 3 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0304-00 - Cylinder 4 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0305-00 - Cylinder 5 Misfire - in Active or Stored status set…

DODGE · 2026-02-27

Flash: Powertrain Control Module (PCM) Updates **Customers may experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle may SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0300-00 - Multiple Cylinder Misfire - in Active or Stored status set during cold start catalyst heating. ● P0301-00 - Cylinder 1 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0302-00 - Cylinder 2 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0303-00 - Cylinder 3 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0304-00 - Cylinder 4 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0305-00 - Cylinder 5 Misfire - in Active or Stored status…

DODGE · 2026-02-27

Flash: Powertrain Control Module (PCM) Updates Customers may experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle may SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0300-00 - Multiple Cylinder Misfire - in Active or Stored status set during cold start catalyst heating. ● P0301-00 - Cylinder 1 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0302-00 - Cylinder 2 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0303-00 - Cylinder 3 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0304-00 - Cylinder 4 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0305-00 - Cylinder 5 Misfire - in Active or Stored status set…

RAM · 2026-02-14

Flash: Powertrain Control Module (PCM) Updates Customers **must** experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle **must** SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0300-00 - Multiple Cylinder Misfire - in Active or Stored status set during cold start catalyst heating. ● P0301-00 - Cylinder 1 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0302-00 - Cylinder 2 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0303-00 - Cylinder 3 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0304-00 - Cylinder 4 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0305-00 - Cylinder 5 Misfire - in Active or Stored…

RAM · 2026-02-14

Flash: Powertrain Control Module (PCM) Updates **Customers may experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle may SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0300-00 - Multiple Cylinder Misfire - in Active or Stored status set during cold start catalyst heating. ● P0301-00 - Cylinder 1 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0302-00 - Cylinder 2 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0303-00 - Cylinder 3 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0304-00 - Cylinder 4 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0305-00 - Cylinder 5 Misfire - in Active or Stored status…

RAM · 2026-02-04

Flash: Powertrain Control Module (PCM) Updates Customers may experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle may exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0300-00 - Multiple Cylinder Misfire - in Active or Stored status set during cold start catalyst heating. ● P0301-00 - Cylinder 1 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0302-00 - Cylinder 2 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0303-00 - Cylinder 3 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0304-00 - Cylinder 4 Misfire - in Active or Stored status set during cold start catalyst heating. ● P0305-00 - Cylinder 5 Misfire - in Active or Stored status set during…

HONDA · 2026-02-01

Service Bulletin - The piston ring function deteriorates due to ring low wear toughness and sticking from sludge. Oil adheres to the spark plug leading to carbon fouling and misfire. This can set DTCs P0301 No. 1 cylinder misfire detected, P0302 No. 2 cylinder misfire detected, P0303 No. 3 cylinder misfire detected, P0304 No. 4 cylinder misfire detected, and cause the MIL to come on.

HONDA · 2026-02-01

Service Bulletin - The piston ring function deteriorates due to ring low wear toughness and sticking from sludge. Oil adheres to the spark plug leading to carbon fouling and misfire. This can set DTCs P0301 No. 1 cylinder misfire detected, P0302 No. 2 cylinder misfire detected, P0303 No. 3 cylinder misfire detected, P0304 No. 4 cylinder misfire detected, and cause the MIL to come on.

FORD, LINCOLN · 2026-01-16

Some 2016-2017 Edge/MKX, 2017 Continental/Fusion/MKZ vehicles equipped with a 2.7L or 3.0L EcoBoost engine and built on 1-Apr-2016 and through 1-Jan-2017 may exhibit white or blue smoke from the exhaust, rough idle in neutral or park at normal operating temperature or after a hot restart. The vehicle may also exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTCs) P0300, P0301, P0302, P0303, P0304, P0305, P0306 and/or P0316, P0524 and/or P06DD with excessive oil consumption. Oil consumption may be 1 Liter (1 quart) in less than 4,800 km (3,000 miles). This may be due to the valve guides. To correct the condition replace the cylinder heads. During service and repair, achieving proper torque of the crankshaft pulley bolt is critical. Incorrect torque may…

JEEP · 2025-12-20

Not applicable to vehicles built for US market. Fuel Injector Leak Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0087-00 - Fuel Line Pressure Sensor - Bank 1 - Pressure Below Limit. ● P0300-00 - Multiple Cylinder Misfire. ● P0301-00 - Cylinder 1 Misfire. ● P0302-00 - Cylinder 2 Misfire. ● P0303-00 - Cylinder 3 Misfire. ● P0304-00 - Cylinder 4 Misfire. ● P006C-00 - Air Pressure and Temperature Sensor - Correlation. Customers may also comment on one or more of the following: ● Unstable idle. ● Abnormal engine noise This bulletin involves diagnosing and possibly replacing the fuel injectors and the high pressure tube.

JEEP · 2025-12-18

Not applicable to vehicles built for US market. Fuel Injector Leak Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0087-00 - Fuel Line Pressure Sensor - Bank 1 - Pressure Below Limit. ● P0300-00 - Multiple Cylinder Misfire. ● P0301-00 - Cylinder 1 Misfire. ● P0302-00 - Cylinder 2 Misfire. ● P0303-00 - Cylinder 3 Misfire. ● P0304-00 - Cylinder 4 Misfire. ● P006C-00 - Air Pressure and Temperature Sensor - Correlation. Customers may also comment on one or more of the following: ● Unstable idle. ● Abnormal engine noise This bulletin involves diagnosing and possibly replacing the fuel injectors and the high pressure tube.

JEEP · 2025-11-08

Not applicable to vehicles built for US market. Fuel Injector Leak Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0087-00 - Fuel Line Pressure Sensor - Bank 1 - Pressure Below Limit. ● P0300-00 - Multiple Cylinder Misfire. ● P0301-00 - Cylinder 1 Misfire. ● P0302-00 - Cylinder 2 Misfire. ● P0303-00 - Cylinder 3 Misfire. ● P0304-00 - Cylinder 4 Misfire. ● P006C-00 - Air Pressure and Temperature Sensor - Correlation. Customers may also comment on one or more of the following: ● Unstable idle. ● Abnormal engine noise This bulletin involves diagnosing and possibly replacing the fuel injectors and the high pressure tube.

RAM · 2025-10-22

Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● **P06DD-00 - Engine Oil Pressure Control Circuit Performance/Stuck Off. ● P0073-00 - Ambient Air Temperature Sensor Circuit "A" High. ● P0071-00 - Ambient Air Temperature Sensor Performance. ● P2C90-00 - Crankcase Ventilation System - Hose "A" Disconnected. ● P1CEA-00 - Boost Side EVAP Purge System Performance. ● P05BD-00 - Stop-start Mode Switch Range/Performance. ● P00C6-00 - Fuel Rail Pressure Too Low - Engine Cranking. ● U0673-00 - Lost Communication With Ion Sense Module.** ● P00C6-00 - Fuel Rail Pressure Too Low - Engine Cranking - in ACTIVE or STORED status. ●…