Service bulletin 1801521

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
Type	Service bulletin
NHTSA id	10220603
Published by NHTSA	2022-09-26
Manufacturer's number	1801521
Manufacturer's date	2021-02-05
NHTSA component	SERVICE BRAKES; ELECTRICAL SYSTEM; POWER TRAIN; BACK OVER PREVENTION; EXTERIOR LIGHTING; FUEL SYSTEM, DIESEL; FUEL SYSTEM, GASOLINE

NHTSA's summary

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.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Brakes, Driver assistance, Electrical system, Fuel system, Lighting, Transmission and driveline, Backup camera

Trouble codes named

P0299, P0301, P0302, P0303, P0304, P0305, P0306, P061B, P064B, P1451, P1C54, P1D73, P20E8, P242F, P2463, P2706

Vehicles listed
RAM 3500	2020
RAM 4500	2020

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
20V191000	2020-09-10. BACK OVER PREVENTION: SENSING SYSTEM: CAMERA

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
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1800824	2024-03-18. Service bulletin. 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
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