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Service bulletins for the 2021 Ram 4500

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.

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

By type

By component

By trouble code

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

Bulletins, newest first
21-039-262026-05-20. Service bulletin. POWER TRAIN. Replace K1 Clutch / Input Shaft Assembly Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set the following Diagnostic Trouble Code (DTC): ● P0731-00 - Gear 1 Shift Incorrect Ratio (This DTC will set during a key cycle and shifting into Drive). Customers must also comment on the following: ● The transmission will not shift into or out of 1st - 4th gears. 5th and reverse gears are still available This bulletin involves replacing the K1 clutch and possibly the K1 input shaft drum sub-assembly. These repairs are to be performed only if the vehicle is inoperable due to K1 clutch failure
21-039-262026-05-13. Service bulletin. POWER TRAIN. Replace K1 Clutch / Input Shaft Assembly Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set the following Diagnostic Trouble Code (DTC): ● P0731-00 - Gear 1 Shift Incorrect Ratio (This DTC will set during a key cycle and shifting into Drive). Customers must also comment on the following: ● The transmission will not shift into or out of 1st - 4th gears. 5th and reverse gears are still available This bulletin involves replacing the K1 clutch and possibly the K1 input shaft drum sub-assembly. These repairs are to be performed only if the vehicle is inoperable due to K1 clutch failure
S25160000012025-10-29. Service bulletin. POWER TRAIN. Driveline Vibration. Prop Shaft Diagnostic Information.
91006422025-08-13. Service bulletin. POWER TRAIN. When customer complaint is related to inoperative 4 Wheel Drive shifter, loss of 4WD function and/or 4WD related MIL please reference SOL Case #S2508000062 prior to replacement of Transfer Case shift motor.
03-001-25 REV. A2025-02-19. Service bulletin. POWER TRAIN; UNKNOWN OR OTHER. "Clicking Noise While In 4WD Customers may experience the following: ● Ratcheting, click, or clicking noise in 4WD while turning. This bulletin involves replacing the front driveshaft."
03-001-252025-02-11. Service bulletin. POWER TRAIN. "Clicking Noise While In 4WD ustomers may experience the following: ● Ratcheting, click, or clicking noise in 4WD while turning. his bulletin involves replacing the front driveshaft"
1023872025-01-04. Service bulletin. POWER TRAIN. SEAL - OUTPUT SHAFT
1023892025-01-04. Service bulletin. POWER TRAIN. SEAL - OUTPUT SHAFT
21-051-242024-10-01. Service bulletin. POWER TRAIN. "Replace K1 Clutch / Input Shaft Assembly Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set the following Diagnostic Trouble Code (DTC): ● P0731-00 - Gear 1 Shift Incorrect Ratio (This DTC will set during a key cycle and shifting into Drive). Customers may also comment on the following: ● The transmission will not shift into or out of 1st - 4th gears. 5th and reverse gears are still available. **This bulletin involves replacing the K1 clutch and possibly the K1 input shaft drum sub-assembly. These repairs are to be performed only if the vehicle is inoperable due to K1 clutch failure. ** "
1006812024-10-01. Warranty extension. UNKNOWN OR OTHER; ENGINE; POWER TRAIN. Warranty Bulletin D-24-16 (XR1) Urea Delivery Module – Select 2019 - 2022 RAM Trucks (DJ/D2/DD/DP)
1005992024-09-24. Warranty extension. POWER TRAIN. FCA Caribbean Warranty Bulletin ID-24-16 Rev. Announces the addition of the Rear Axle Assembly replacement for 2019 - 2024 RAM 3500 Cab Chassis (DD), RAM 4500/ 5500 Cab Chassis (DP), RAM 3500 Pickup (D2), RAM 2500 Pickup (DJ), RAM 1500 Pickup (DS) and RAM 1500 Pickup (DT) vehicles to the Powertrain Pre-Authorization program to ensure proper repair of Rear Axle Assembly failures and to assist in quality improvements. REV.A
1005952024-09-24. Warranty extension. POWER TRAIN. WARRANTY BULLETIN D-24-15 announces the addition of the Rear Axle Assembly replacement for 2019 - 2024 RAM 3500 Cab Chassis (DD), RAM 4500/ 5500 Cab Chassis (DP), RAM 3500 Pickup (D2), RAM 2500 Pickup (DJ), RAM 1500 Pickup (DS) and RAM 1500 Pickup (DT) vehicles to the Powertrain Pre-Authorization program for all dealers (Base, Plus & Premium) to ensure proper repair of Rear Axle Assembly failures and to assist in quality improvements. REV.A
18017232024-01-02. Service bulletin. POWER TRAIN; BACK OVER PREVENTION; ELECTRICAL SYSTEM; AIR BAGS. Flash: Powertrain Control Module (PCM) Updates Customer or technician may experience the following: ? High frequency exhaust noise at idle after cold start. ? Power Take Off (PTO) disable to high engine oil temperature. ? Multiple Displacement System (MDS) transition causing a transmission clunk noise under light throttle when coasting in fourth gear. This bulletin involves reprogramming the PCM with the latest available software.
932382023-10-30. Service bulletin. POWER TRAIN. AISIN K1 SNAP RING REPLACEMENT
21002232023-10-02. Service bulletin. POWER TRAIN. K1 Clutch Snap Ring Repair Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation, a technician may find the following Diagnostic Trouble Code (DTC) has been set: ? P0731-00 - Gear 1 Shift Incorrect Ratio (This DTC will set during a key cycle and shifting into Drive). Customers may also comment on the following: ? The transmission will not shift into/or out of 1st - 4th gears. 5th and reverse gears are still available. This bulletin involves replacing the K1 clutch drum snap ring and possibly the K1 input shaft drum subassembly.
18078232023-08-21. Service bulletin. POWER TRAIN:MANUAL TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); ELECTRICAL SYSTEM; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); POWER TRAIN. Flash: Powertrain Control Module (PCM) Updates Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation, a technician may find one or more of the following DTCs have been set: ? U0418-00 - Implausible Data Received From Brake System Control Module 1. ? P061A - Level 2 Torque Performance. Customers may also experience the following: ? **Driveline bumps and rumbles when lightly applying the accelerator pedal in traffic or at other low vehicle speeds such as parking lot maneuvers.** ? Transmission hard upshifts, rough/bump during low gear 1-2 and 2-3 at 40-64 kph (25-40 mph). This bulletin involves reprogramming the PCM with the latest available software.
03003232023-08-21. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. Clicking Noise While In 4wd Ratcheting, Click, or Clicking noise in 4WD while turning. This bulletin involves replacing the front driveshaft.
18017232023-04-17. Service bulletin. BACK OVER PREVENTION; AIR BAGS; POWER TRAIN; ELECTRICAL SYSTEM. Flash: Powertrain Control Module (PCM) Updates Customer or technician may experience the following: ? High frequency exhaust noise at idle after cold start. ? Power Take Off (PTO) disable to high engine oil temperature. ? Multiple Displacement System (MDS) transition causing a transmission clunk noise under light throttle when coasting in fourth gear. This bulletin involves reprogramming the PCM with the latest available software.
S1623000028 Rev.2023-02-13. Service bulletin. VEHICLE SPEED CONTROL; BACK OVER PREVENTION; POWER TRAIN; VISIBILITY; PARKING BRAKE. Outside Power Fold Rearview Mirror Noise Or Loose At Pivot. Mirror Contacts Door Window Glass In The Folded Position.
18127222023-01-17. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN. Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the Engine Control Module (ECM) / Powertrain Control Module (PCM) with the latest available software. PCM software related to this Technical Service Bulletin (TSB) is included within the Y43 Recall. If not already completed, please perform the Y43 recall if the vehicle is on the recall VIN list. For all other vehicles perform the Repair Procedure below. 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. P0299-00 - Turbocharger Underboost. P1451-00 - Diesel Particulate Filter System Performance. The following improvements are also included in this update: Idle stability improvement. Fuel system run-up test routine, wiTECH improvement. Aftertreatment system performance test routine, wiTECH improvement. Power Take Off (PTO) system improvements. Enabling Estop for split shaft PTO systems. Oil pressure switch modifications. Urea (DEF fluid) level sensor calibration update, to help prevent bumps in DEF level gauge.
S21210000102023-01-17. Service bulletin. EQUIPMENT:ELECTRICAL; POWER TRAIN. Service 4WD Lamp On, 4WD System Does Not Work, 4WD Service Lamp Flashing, Front Axle Disconnect Does Not Engage Or Disengage
08088212023-01-17. Service bulletin. POWER TRAIN. Radio Enhancements This bulletin involves updating the radio software level to 2036.06. Customers may experience the following:Product plan UUID is not correct in Carplay®. Carplay audio does not always resume. Battery save vs. Battery Charge toggles back to Battery Charge after sleep cycle. When ?Charge Now? is selected on key-off outside of the charging schedule ? it does nothing. In addition, the following enhancements are included:Update power supply source from 1 amp to 2.1 amps. GOOGLE® certification enhancements - screen flickers
S1923000015RevB2023-01-09. Service bulletin. POWER TRAIN. Transmission Column Shifter Lever Feels Loose
2101922REVA2022-12-12. 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 comment on one or more of the following: Harsh shifts. Poor shift quality, with light pedal.(Sales Codes ETM and ETN Only). Poor shift quality, 32-48 kph (20-30 mph), at low rpm with light to medium pedal apply, typically tipping in from zero pedal.(Sales Codes ETM and ETN Only). Coasting shift bump with exhaust brake and/or tow/haul active.(Sales Codes ETM and ETN Only). Poor shift quality, often when increasing pedal during a shift.(Sales Code ESB Only). Squawk/chirp/squeak type noise during a 3-4 upshift.(D2 Only). Poor 1-2 upshift quality.(D2 with ETM or DD/DP with Sales Code ESB Only). When decelerating from a 1 to 2 gear shift, the vehicle may have a harshshift. From a 1 to 2 gear change there may be a perceived bump feeling, whilehaving a light pedal(Sales Codes ETL and ETN Only). A harsh shift from a 2 to 3 gear shift while at almost or wide openthrottle. A harsh shift from a 3 to 4 shift and heavy on the pedal, lifting offthe pedal, then back on the pedal again. While coasting down a grade, an abrupt deceleration may be felt. A clunk heard when shifting from park to reverse or drive. Cold engine flare during a shift. A delay when coasting down, vehicle is in a downshift at low speedsand then trying to accelerate. (The vehicle will have a hesitation as the vehicle tries to change gears to accommodate the new pedaldemand). Excessive shifting(DD and DP Only). Engine flare caused by the transmission releasing the clutch too early duringa 1 to 2 shift.
18127222022-10-17. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM. Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the Engine Control Module (ECM) / Powertrain Control Module (PCM) with the latest available software. PCM software related to this Technical Service Bulletin (TSB) is included within the Y43 Recall. If not already completed, please perform the Y43 recall if the vehicle is on the recall VIN list. For all other vehicles perform the Repair Procedure below. 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. P0299-00 - Turbocharger Underboost. P1451-00 - Diesel Particulate Filter System Performance. The following improvements are also included in this update: Idle stability improvement. Fuel system run-up test routine, wiTECH improvement. Aftertreatment system performance test routine, wiTECH improvement. Power Take Off (PTO) system improvements. Enabling Estop for split shaft PTO systems. Oil pressure switch modifications. Urea (DEF fluid) level sensor calibration update, to help prevent bumps in DEF level gauge.

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