# P0304 on the 2020 Ram 4500

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.

## Bulletins for this model year that name P0304

- [10251873](https://open.wenmarpro.com/bulletins/10251873), 2024-03-18: Flash: Powertrain Control Module \(PCM\) Updates Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find one or more of the following Diagnostic Trouble Codes \(DTCs\) have been set: P0506\-00 \- Idle Control System RPM \- Lower Than Expected.P0607\-00 \- ECU Internal Performance. P20E8\-00 \- Reductant Pressure Too Low. P0301\-00 \- Cylinder 1 Misfire. P0302\-00 \- Cylinder 2 Misfire. P0303\-00 \- Cylinder 3 Misfire. P0304\-00 \- Cylinder 4 Misfire. P0305\-00 \- Cylinder 5 Misfire. P0306\-00 \- Cylinder 6 Misfire. P0299\-00 \- Turbocharger Underboost. P1D73\-00 \- AGS Performance. P0626 \- Generator Field Control Circuit High. P218F \- Reductant No Flow Detected. P2002 \- Diesel Particulate Filter Efficiency Below Threshold. P24A5 \- EGR Cooler Bypass Bank 1 Control Stuck. P0191 \- Fuel Rail Pressure Sensor Circuit Performance. P0461 \- Fuel Level Sensor 1 Performance. P0401 \- EGR System Performance. P20EE \- SCR NOx Catalyst Efficiency Below Threshold \- Bank 1. P061A \- Level 2 Torque Performance. P061B \- Internal Control Module Torque Calculation Performance. P061E \- Internal Control Module Brake Signal Performance. P062C \- ETC Level 2 MPH Performance. P0106 \- Manifold Absolute Pressure Sensor Performance \(In extreme cold ambient temperatures\). P0116 \- Engine Coolant Temperature Sensor Performance. P0420 \- Catalyst System Efficiency Bank 1. P1507 \- Crankcase Filter Restriction. P203F \- Reductant Level Too Low. P226C \- Turbocharger Boost Control ?A? Slow Response \(In extreme cold ambient temperatures\). P2579 \- Turbocharger Speed Sensor Circuit. U0101 \- Lost Communication with TCM. U02A3 \- Lost of Communication with PM Sensor. U3017 \- Control Module Timer/Clock Performance. Customers may also experience one or more of the following Power
- [10223191](https://open.wenmarpro.com/bulletins/10223191), 2022-10-17: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the Engine Control Module \(ECM\) / PowertrainControl Module \(PCM\) with the latest available software. Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find that one or moreof the following Diagnostic Trouble Codes \(DTCs\) have been set: P0506\-00\-Idle Control System Rpm \- Lower Than Expected. P0088 \- Fuel Rail Pressure Too High \- Bank 1\(Sym Cam Only\) P0607\-00 \- ECU Internal Performance. P20E8\-00 \- Reductant Pressure Too Low. P0301\-00 \- Cylinder 1 Misfire\(Sym Cam Pump Only\). P0302\-00 \- Cylinder 2 Misfire\(Sym Cam Pump Only\). P0303\-00 \- Cylinder 3 Misfire\(Sym Cam Pump Only\). P0304\-00 \- Cylinder 4 Misfire\(Sym Cam Pump Only\). P0305\-00 \- Cylinder 5 Misfire\(Sym Cam Pump Only\). P0306\-00 \- Cylinder 6 Misfire\(Sym Cam Pump Only\). P1C54\-00 \- SCR NOx Catalyst Missing. P242F\-00 \- Diesel Particulate Filter Restriction \- Ash Accumulation\(68RFE Only\). P2463\-00 \- Diesel Particulate Filter Restriction \- Soot Accumulation Bank 1\(68RFE Only\). P1451\-00 \- Diesel Particulate Filter System Performance\(68RFE Only\). P0299\-00 \- Turbocharger Underboost. P2706\-00 \- MS Solenoid Circuit \(68RFE Only\). P1D73\-00 \- AGS Performance. P061B \- Internal Control Module Torque Calculation Performance. P064B\-00 \- PTO Control Module. The customer may also notice the following: PTO Customers: Allows E\-Stop to work in any gear. PTO customers that use remote start: Prevents PTO cancellation in cabfrom disabling remote start. Harsh downshift clunk during exhaust brake deceleration. DEF gauge erratic when DEF level is low. Stall when putting in reverse in cold ambient temps. Engine stumble during engine warm up. Unstable idle when AC compressor cycles. Power Take Off \(PTO\) intermittently turns off with no DTCs. In addition the following software enhancements are included:Engine oil pressure switch modification. Oil Change Monitor Improvements For Severe Duty Operati
- [10220809](https://open.wenmarpro.com/bulletins/10220809), 2022-09-26: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the Engine Control Module \(ECM\) / PowertrainControl Module \(PCM\) with the latest available software. Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find that one or moreof the following Diagnostic Trouble Codes \(DTCs\) have been set: P0506\-00\-Idle Control System Rpm \- Lower Than Expected. P0088 \- Fuel Rail Pressure Too High \- Bank 1\(Sym Cam Only\) P0607\-00 \- ECU Internal Performance. P20E8\-00 \- Reductant Pressure Too Low. P0301\-00 \- Cylinder 1 Misfire\(Sym Cam Pump Only\). P0302\-00 \- Cylinder 2 Misfire\(Sym Cam Pump Only\). P0303\-00 \- Cylinder 3 Misfire\(Sym Cam Pump Only\). P0304\-00 \- Cylinder 4 Misfire\(Sym Cam Pump Only\). P0305\-00 \- Cylinder 5 Misfire\(Sym Cam Pump Only\). P0306\-00 \- Cylinder 6 Misfire\(Sym Cam Pump Only\). P1C54\-00 \- SCR NOx Catalyst Missing. P242F\-00 \- Diesel Particulate Filter Restriction \- Ash Accumulation\(68RFE Only\). P2463\-00 \- Diesel Particulate Filter Restriction \- Soot Accumulation Bank 1\(68RFE Only\). P1451\-00 \- Diesel Particulate Filter System Performance\(68RFE Only\). P0299\-00 \- Turbocharger Underboost. P2706\-00 \- MS Solenoid Circuit \(68RFE Only\). P1D73\-00 \- AGS Performance. P061B \- Internal Control Module Torque Calculation Performance. P064B\-00 \- PTO Control Module. The customer may also notice the following: PTO Customers: Allows E\-Stop to work in any gear. PTO customers that use remote start: Prevents PTO cancellation in cabfrom disabling remote start. Harsh downshift clunk during exhaust brake deceleration. DEF gauge erratic when DEF level is low. Stall when putting in reverse in cold ambient temps. Engine stumble during engine warm up. Unstable idle when AC compressor cycles. Power Take Off \(PTO\) intermittently turns off with no DTCs. In addition the following software enhancements are included:Engine oil pressure switch modification.
- [10220603](https://open.wenmarpro.com/bulletins/10220603), 2022-09-26: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the Engine Control Module \(ECM\) / Powertrain Control Module \(PCM\) with the latest available software. Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find that one or more of the following Diagnostic Trouble Codes \(DTCs\) have been set:P20E8\-00 \- Reductant Pressure Too Low. P0301\-00 \- Cylinder 1 Misfire\(Sym Cam Pump Only\). P0302\-00 \- Cylinder 2 Misfire\(Sym Cam Pump Only\). P0303\-00 \- Cylinder 3 Misfire\(Sym Cam Pump Only\). P0304\-00 \- Cylinder 4 Misfire\(Sym Cam Pump Only\). P0305\-00 \- Cylinder 5 Misfire\(Sym Cam Pump Only\). P0306\-00 \- Cylinder 6 Misfire\(Sym Cam Pump Only\). P1C54\-00 \- SCR NOx Catalyst Missing. P242F\-00 \- Diesel Particulate Filter Restriction \- Ash Accumulation\(68RFE Only\). P2463\-00 \- Diesel Particulate Filter Restriction \- Soot Accumulation Bank 1\(68RFE Only\). P1451\-00 \- Diesel Particulate Filter System Performance\(68RFE Only\). P0299\-00 \- Turbocharger Underboost. P2706\-00 \- MS Solenoid Circuit \(68RFE Only\). P1D73\-00 \- AGS Performance. P061B \- Internal Control Module Torque Calculation Performance. P064B\-00 \- PTO Control Module. The customer may also notice the following:Harsh downshift clunk during exhaust brake deceleration. DEF gauge erratic when DEF level is low. Stall when putting in reverse in cold ambient temps. Engine stumble during engine warm up. Unstable idle when AC compressor cycles. Power Take Off \(PTO\) intermittently turns off with no DTCs. In addition the following software enhancements are included:Oil Change Monitor Improvements For Severe Duty Operation. System Improvement for PTO operation. wiTECH Mass Air Flow \(MAF\) data parameter improvement. Enabling wiTECH Particulate Matter \(PM\) Sensor Regeneration Test in PCM ?Misc Functions?. Active Grille Shutter \(AGS\) quality enhancements.
- [10218563](https://open.wenmarpro.com/bulletins/10218563), 2022-08-22: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the Engine Control Module \(ECM\) / Powertrain Control Module \(PCM\) with the latest available software. Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find that one or more of the following Diagnostic Trouble Codes \(DTCs\) have been set: P0607\-00 \- ECU Internal Performance. P20E8\-00 \- Reductant Pressure Too Low. P0301\-00 \- Cylinder 1 Misfire\(Sym Cam Pump Only\). P0302\-00 \- Cylinder 2 Misfire\(Sym Cam Pump Only\). P0303\-00 \- Cylinder 3 Misfire\(Sym Cam Pump Only\). P0304\-00 \- Cylinder 4 Misfire\(Sym Cam Pump Only\). P0305\-00 \- Cylinder 5 Misfire\(Sym Cam Pump Only\). P0306\-00 \- Cylinder 6 Misfire\(Sym Cam Pump Only\). P1C54\-00 \- SCR NOx Catalyst Missing. P242F\-00 \- Diesel Particulate Filter Restriction \- Ash Accumulation\(68RFE Only\). P2463\-00 \- Diesel Particulate Filter Restriction \- Soot Accumulation Bank 1\(68RFE Only\). P1451\-00 \- Diesel Particulate Filter System Performance\(68RFE Only\). P0299\-00 \- Turbocharger Underboost. P2706\-00 \- MS Solenoid Circuit \(68RFE Only\). P1D73\-00 \- AGS Performance. P061B \- Internal Control Module Torque Calculation Performance. P064B\-00 \- PTO Control Module. The customer may also notice the following: Harsh downshift clunk during exhaust brake deceleration. DEF gauge erratic when DEF level is low. Stall when putting in reverse in cold ambient temps. Engine stumble during engine warm up. Unstable idle when AC compressor cycles. Power Take Off \(PTO\) intermittently turns off with no DTCs. In addition the following software enhancements are included: Engine oil pressure switch modification. Oil Change Monitor Improvements For Severe Duty Operation. System Improvement for PTO operation. wiTECH Mass Air Flow \(MAF\) data parameter improvement. Enabling wiTECH Particulate Matter \(PM\) Sensor Regeneration Test in PCM ?Misc Functions?. Active Grille Shutter \(AGS\) quality enhancements.
- [10214636](https://open.wenmarpro.com/bulletins/10214636), 2022-06-27: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the Engine Control Module \(ECM\) / Powertrain Control Module \(PCM\) with the latest available software. Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find that one or more of the following Diagnostic Trouble Codes \(DTCs\) have been set: P0506\-00\-Idle Control System RPM \- Lower Than Expected. P0088 \- Fuel Rail Pressure Too High \- Bank 1. P0607\-00 \- ECU Internal Performance. P20E8\-00 \- Reductant Pressure Too Low. P0301\-00 \- Cylinder 1 Misfire. P0302\-00 \- Cylinder 2 Misfire. P0303\-00 \- Cylinder 3 Misfire. P0304\-00 \- Cylinder 4 Misfire. P0305\-00 \- Cylinder 5 Misfire. P0306\-00 \- Cylinder 6 Misfire. P1C54\-00 \- SCR NOx Catalyst Missing. P242F\-00 \- Diesel Particulate Filter Restriction \- Ash Accumulation\(68RFE Only\). P2463\-00 \- Diesel Particulate Filter Restriction \- Soot Accumulation Bank 1\(68RFE Only\). P1451\-00 \- Diesel Particulate Filter System Performance\(68RFE Only\). P0299\-00 \- Turbocharger Underboost. P2706\-00 \- MS Solenoid Circuit \(68RFE Only\). P1D73\-00 \- AGS Performance. P061B \- Internal Control Module Torque Calculation Performance. P064B\-00 \- PTO Control Module. The customer may also notice the following:PTO Customers: Allows E\-Stop to work in any gear. PTO customers that use remote start: Prevents PTO cancellation in cab from disabling remote start. Harsh downshift clunk during exhaust brake deceleration. DEF gauge erratic when DEF level is low. Stall when putting in reverse in cold ambient temps. Engine stumble during engine warm up. Unstable idle when AC compressor cycles. Power Take Off \(PTO\) intermittently turns off with no DTCs. In addition the following software enhancements are included:Engine oil pressure switch modification. Oil Change Monitor Improvements For Severe Duty Operation. System Improvement for PTO operation. wiTECH Mass Air Flow \(MAF\) data parameter improvement.
- [10212413](https://open.wenmarpro.com/bulletins/10212413), 2022-05-31: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the Engine Control Module \(ECM\) / PowertrainControl Module \(PCM\) with the latest available software. Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find that one or moreof the following Diagnostic Trouble Codes \(DTCs\) have been set: P0506\-00\-Idle Control System Rpm \- Lower Than Expected. P0088 \- Fuel Rail Pressure Too High \- Bank 1\(Sym Cam Only\) P0607\-00 \- ECU Internal Performance. P20E8\-00 \- Reductant Pressure Too Low. P0301\-00 \- Cylinder 1 Misfire\(Sym Cam Pump Only\). P0302\-00 \- Cylinder 2 Misfire\(Sym Cam Pump Only\). P0303\-00 \- Cylinder 3 Misfire\(Sym Cam Pump Only\). P0304\-00 \- Cylinder 4 Misfire\(Sym Cam Pump Only\). P0305\-00 \- Cylinder 5 Misfire\(Sym Cam Pump Only\). P0306\-00 \- Cylinder 6 Misfire\(Sym Cam Pump Only\). P1C54\-00 \- SCR NOx Catalyst Missing. P242F\-00 \- Diesel Particulate Filter Restriction \- Ash Accumulation\(68RFE Only\). P2463\-00 \- Diesel Particulate Filter Restriction \- Soot Accumulation Bank 1\(68RFE Only\). P1451\-00 \- Diesel Particulate Filter System Performance\(68RFE Only\). P0299\-00 \- Turbocharger Underboost. P2706\-00 \- MS Solenoid Circuit \(68RFE Only\). P1D73\-00 \- AGS Performance. P061B \- Internal Control Module Torque Calculation Performance. P064B\-00 \- PTO Control Module. The customer may also notice the following: PTO Customers: Allows E\-Stop to work in any gear. PTO customers that use remote start: Prevents PTO cancellation in cabfrom disabling remote start. Harsh downshift clunk during exhaust brake deceleration. DEF gauge erratic when DEF level is low. Stall when putting in reverse in cold ambient temps. Engine stumble during engine warm up. Unstable idle when AC compressor cycles. Power Take Off \(PTO\) intermittently turns off with no DTCs. In addition the following software enhancements are included:Engine oil pressure switch modification. Oil Change Monitor Improvements For Severe Duty Ope
- [10188807](https://open.wenmarpro.com/bulletins/10188807), 2021-03-15: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the Engine Control Module \(ECM\) / Powertrain Control Module \(PCM\) with the latest available software. Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find that one or more of the following Diagnostic Trouble Codes \(DTCs\) have been set:P20E8\-00 \- Reductant Pressure Too Low. P0301\-00 \- Cylinder 1 Misfire\(Sym Cam Pump Only\). P0302\-00 \- Cylinder 2 Misfire\(Sym Cam Pump Only\). P0303\-00 \- Cylinder 3 Misfire\(Sym Cam Pump Only\). P0304\-00 \- Cylinder 4 Misfire\(Sym Cam Pump Only\). P0305\-00 \- Cylinder 5 Misfire\(Sym Cam Pump Only\). P0306\-00 \- Cylinder 6 Misfire\(Sym Cam Pump Only\). P1C54\-00 \- SCR NOx Catalyst Missing. P242F\-00 \- Diesel Particulate Filter Restriction \- Ash Accumulation\(68RFE Only\). P2463\-00 \- Diesel Particulate Filter Restriction \- Soot Accumulation Bank 1\(68RFE Only\). P1451\-00 \- Diesel Particulate Filter System Performance\(68RFE Only\). P0299\-00 \- Turbocharger Underboost. P2706\-00 \- MS Solenoid Circuit \(68RFE Only\). P1D73\-00 \- AGS Performance. P061B \- Internal Control Module Torque Calculation Performance. P064B\-00 \- PTO Control Module. The customer may also notice the following:Harsh downshift clunk during exhaust brake deceleration. DEF gauge erratic when DEF level is low. Stall when putting in reverse in cold ambient temps. Engine stumble during engine warm up. Unstable idle when AC compressor cycles. Power Take Off \(PTO\) intermittently turns off with no DTCs. In addition the following software enhancements are included:Oil Change Monitor Improvements For Severe Duty Operation. System Improvement for PTO operation. wiTECH Mass Air Flow \(MAF\) data parameter improvement. Enabling wiTECH Particulate Matter \(PM\) Sensor Regeneration Test in PCM ?Misc Functions?. Active Grille Shutter \(AGS\) quality enhancements.