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Service bulletins for the 2021 Ram 1500

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.

1129 on file from NHTSA, as of 2026-10-19.

By type

By component

By trouble code

By topic

Only bulletins with component: Transmission and driveline are shown. Show all

Bulletins, newest first
21-019-212021-06-28. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM. Flash: Transmission Control Module (TCM) Updates This bulletin involves reprogramming the TCM with the latest available software. Customers may experience the follwing:Unable to set desired gear manually from the steering wheel controls.
21-018-212021-06-28. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN. Flash: Transmission Control Module (TCM) Updates This bulletin involves reprogramming the TCM with the latest available software. The customer may describe one or more of the following:During a 2 - 3 transmission upshift, the engine is hitting rev limit. Hesitation feel during a pedal tip in, while engine is warming up below 1 °C (30 °F) ambient temp.
18-050-212021-06-28. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN. Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the PCM with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find that the one or more of the following Diagnostic Trouble Codes (DTCs) have been set: P0133 - O2 Sensor 1/1 Slow Response. P0153 - O2 Sensor 2/1 Slow Response. P0171 - Fuel System 1/1 Lean. P0174 - Fuel System 2/1 Lean. 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. B2286 - Calibration Not Learned / Lost Calibration. The customer may also experience one or more of the following:Hesitation feel during a pedal tip in, while engine is warming up below -1 °C (30 °F) ambient temp. During a 2 - 3 transmission upshift, the engine is hitting rev limit. ?Service Suspension? message in Instrument Panel Cluster (IPC) on start up.
18-048-212021-06-28. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM. Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the PCM with the latest available software. The customer may experience the following:LED light in the Start/Stop button will not illuminate when pressed.
742442021-06-28. Service bulletin. POWER TRAIN. Warranty Bulletin D-20-23 Part Order Restriction Program - 48V Power Pack Unit (PPU) - Select 2018 - 2021 Jeep Wrangler (JL) and 2019 - 2021 RAM (DT) (Rev. A)
08-067-212021-05-24. Service bulletin. ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM; WHEELS; STEERING; POWER TRAIN; EXTERIOR LIGHTING; AIR BAGS. Flash: Drivetrain Control Module (DTCM) Diagnostic and System Improvements This bulletin involves reprogramming the DTCM with the latest available software. The technician may find one or more of the following DTCs:U1440 - Implausible Transfer Case Ratio High Received. U0403-00 - Implausible Data Received From T-case. C1403-92 - Transfer Case Range Position Sensor-Performance Or Incorrect Operation(2019-2020 Vehicles Only). If only DTC C1403 is present, follow normal diagnostic procedures before updatingthe DTCM.In addition the customer may describe one or more of the following:Traction Control System light is illuminated. A driveline bump can be heard/felt occasionally when the driver is steady on the throttle at about 20-30% on a flat road while in 4WDAUTO(2019-2020 Vehicles Only). An excessive electric motor clicking sound from the middle of the vehicle/transfer case area, when on and off the throttle(2019-2020 Vehicles Only). An excessive electric motor clicking sound with steering wheel movement, most notable in parking lot or low speed maneuvering(2019-2020 Vehicles Only). A ?Service 4WD? message/fault without commanding a transfer case shift(2019-2020 Vehicles Only).If only the ?Service 4WD? message/fault is displayed in the Instrument Panel Cluster (IPC) and no other symptom/conditionsare present, follow normal diagnostic procedures before updating the DTCM(2019-2020 Vehicles Only). The blinking of the ?4WD Low? and ?4WD High? indicator lights at the same time, on the transfer case selector switch.If both 4WD indicator lights on the transfer case selector switch are blinking and no other symptom/conditions are present,follow normal diagnostic procedures before updating the DTCM(2019-2020 Vehicles Only). During highway/freeway speeds, a bump in the driveline may be felt. This could also be described as a harsh transmission shift(2019-2020 Vehicles Only).
S21080001042021-05-24. Service bulletin. POWER TRAIN. No Start, On Stop Start Vehicles A MIL Lamp On With DTC P0A97 Combined With The No Start
S2008000113 Rev.2021-05-24. Service bulletin. POWER TRAIN. No Start Intermittently, Vehicle Requires Multiple Keyless Push To Start Attempts To Start Vehicle, Intermittent Key Not Detected Message
03-001-212021-04-26. Service bulletin. POWER TRAIN. Outer Halfshaft Axle Boots Leaking Grease This bulletin involves inspecting the both outer halfshaft axle boots for tears. The customer or technician may experience a axle grease leaking out of one or both of the outer halfshaft axle boots, this can happen within 804 Km (500 miles).
09-003-21 REV. A2021-04-26. Service bulletin. EXTERIOR LIGHTING; POWER TRAIN. Transmission Oil Cooler Lines Not Fully Connected This bulletin involves inspecting the Transmission Oil Cooler (TOC) lines and reconnectingif necessary. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find one or more ofthe following Diagnostic Trouble Codes (DTCs). P1D90-00 Incorrect Gear Ratio - Clutch 2 Defective. P1D91-00 Incorrect Gear Ratio - Clutch 3 Defective. P1D92-00 Incorrect Gear Ratio - Clutch 4 Defective. P1D93-00 Incorrect Gear Ratio - Clutch 5 Defective. P1D95-00 Tcm Clutch Failure Undetermined. P1B14-00 Park-By-Wire - Unintended Park Position. P1B13-00 Park-By-Wire - Unintended Out Of Park Position. P1D99-00 Incorrect Gear Ratio: Clutch B Or E Defective. P1D9A-00 Incorrect Gear Ratio: Clutch C Or D Defective. P1D95-00 Tcm Clutch Failure Undetermined. P07E4-00 Unable To Engage Park. P1DCD-00 Tcm Monitoring Processor Performance - Multiple Clutches Locked Up. P0735-00 Gear 5 Shift Incorrect Ratio. P0919-00 Gear Shift Position Control Error. Customers may also experience the following:Transmission fluid leaking under vehicle. The vehicle will not shift. Slow shifting between gears.
09-003-212021-04-26. Service bulletin. POWER TRAIN; EXTERIOR LIGHTING. Transmission Oil Cooler Lines Not Fully Connected This bulletin involves inspecting the Transmission Oil Cooler (TOC) lines and reconnecting if necessary. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find one or more ofthe following Diagnostic Trouble Codes (DTCs). P1D90-00 Incorrect Gear Ratio - Clutch 2 Defective. P1D91-00 Incorrect Gear Ratio - Clutch 3 Defective. P1D92-00 Incorrect Gear Ratio - Clutch 4 Defective. P1D93-00 Incorrect Gear Ratio - Clutch 5 Defective. P1D95-00 Tcm Clutch Failure Undetermined. P1B14-00 Park-By-Wire - Unintended Park Position. P1B13-00 Park-By-Wire - Unintended Out Of Park Position. P1D99-00 Incorrect Gear Ratio: Clutch B Or E Defective. P1D9A-00 Incorrect Gear Ratio: Clutch C Or D Defective. P1D95-00 Tcm Clutch Failure Undetermined. P07E4-00 Unable To Engage Park. P1DCD-00 Tcm Monitoring Processor Performance - Multiple Clutches Locked Up. P0735-00 Gear 5 Shift Incorrect Ratio. P0919-00 Gear Shift Position Control Error. Customers may also experience the following:Transmission fluid leaking under vehicle. The vehicle will not shift. Slow shifting between gears.
18-028-212021-04-26. Service bulletin. FUEL SYSTEM, GASOLINE; EXTERIOR LIGHTING; SERVICE BRAKES, HYDRAULIC; ELECTRICAL SYSTEM; BACK OVER PREVENTION; FUEL SYSTEM, DIESEL; POWER TRAIN; AIR BAGS. Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the PCM with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation, a technician may find one or more of the following Diagnostic Trouble Codes (DTCs) have been set: P0524 - Low oil pressure (during start up in cold ambient temps). P249C-00 - Excessive Time To Enter Closed Loop Reductant Injection Control. P02E8-00 - Diesel Intake Air Flow Position Sensor Circuit Low. P20FB-00 - Reductant Pump 2 Control Performance. P065A-00 - Generator System Performance. P00AF-00 - Turbocharger Boost Control Module "A" Performance. P200A-00 - Intake Manifold Runner Performance - Bank 1. P200B-00 - Intake Manifold Runner Performance - Bank 2. P0106-00 - Manifold Absolute Pressure Sensor Performance. Customers may experience the following:Radio may reset during engine idle. Electronic Throttle Control (ETC) lamp turns on. After a long cold soak a stumble/hesitation is felt during the first few light accelerations. Turbo Surge in park or neutral and high Idle. The cruise control and speed limited set speed doesn?t match the speedometer. It could be up to 2.5 kpm (1.5 mph) difference. Other Software enhancements:Speedometer accuracy improvement(s). Cruise control updates. Battery durability improvements in hot ambient temperatures. Improved idle quality during remote start.
21-005-212021-04-26. Service bulletin. ELECTRICAL SYSTEM; EXTERIOR LIGHTING; POWER TRAIN. Flash: Transmission Control Module (TCM) Updates This bulletin involves reprogramming the TCM with the latest available software. Customers may experience the following on a vehicle with less than 64 km (40 miles) on the odometer:A Malfunction Indicator Lamp (MIL) event or failure withnoDiagnostic Trouble Codes (DTCs) and the vehicle has less than 40 miles on the odometer indicates it is likely the vehicle has experienced an unintentional code clear event. Do not use this software update if vehicle odometer has over 64 km (40 miles).
S21080000832021-04-26. Service bulletin. POWER TRAIN. 4Wheel Drive Lamp On, DTC C141C-13-REAR DIFFERENTIAL CONTROL-CIRCUIT OPEN
S21210000022021-04-26. Service bulletin. POWER TRAIN. Transmission Fluid Leak Inspection, Transmission Cooler Line Inspection
09-014-202021-03-01. Service bulletin. EQUIPMENT; POWER TRAIN; EQUIPMENT ADAPTIVE/MOBILITY. Transmission Oil Cooler Line Not Fully Connected This bulletin involves inspecting the Transmission Oil Cooler (TOC) lines and reconnectingif necessary. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find one or more ofthe following Diagnostic Trouble Codes (DTCs).P1D90-00 Incorrect Gear Ratio - Clutch 2 Defective. P1D91-00 Incorrect Gear Ratio - Clutch 3 Defective. P1D92-00 Incorrect Gear Ratio - Clutch 4 Defective. P1D93-00 Incorrect Gear Ratio - Clutch 5 Defective. P1D95-00 Tcm Clutch Failure Undetermined. P1B14-00 Park-By-Wire - Unintended Park Position. P1B13-00 Park-By-Wire - Unintended Out Of Park Position. P1D99-00 Incorrect Gear Ratio: Clutch B Or E Defective. P1D9A-00 Incorrect Gear Ratio: Clutch C Or D Defective. P1D95-00 Tcm Clutch Failure Undetermined. P07E4-00 Unable To Engage Park. P1DCD-00 Tcm Monitoring Processor Performance - Multiple Clutches Locked Up. P0735-00 Gear 5 Shift Incorrect Ratio. P0919-00 Gear Shift Position Control Error. Customers may also experience the following:Transmission fluid leaking under vehicle. The vehicle will not shift. Slow shifting between gears.
S20080001962021-03-01. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); ELECTRICAL SYSTEM:ALTERNATOR/GENERATOR/REGULATOR. Diagnostic Trouble Code (DTC) P065A ? Generator System Performance, Additional Information.
S2025000001 Rev.2020-12-28. Service bulletin. EXTERIOR LIGHTING; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); EQUIPMENT. (Rev. B) Malfunction Indicator Lamp Illumination (MIL). Diagnostic Trouble Code (DTC) P203E ? Reductant Level Sensor 1 Circuit Intermittent-Erratic Set.
S1925000008 Rev.2020-12-21. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); ENGINE; FUEL SYSTEM, DIESEL. (Rev. B) Malfunction Indicator Lamp (MIL) Illumination. Diagnostic Trouble Codes (DTCs) P20E8 ? Reductant Pressure Too Low and/or P208B ? Reductant Pump 1 Control Performance Set.
S2025000001 Rev.2020-12-21. Service bulletin. ELECTRICAL SYSTEM; FUEL SYSTEM, DIESEL:STORAGE:TANK ASSEMBLY; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM). (Rev. B) Malfunction Indicator Lamp Illumination (MIL). Diagnostic Trouble Code (DTC) P203E ? Reductant Level Sensor 1 Circuit Intermittent-Erratic Set.

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.