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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: Engine are shown. Show all

Bulletins, newest first
S1408000384 REV.F2024-07-02. Service bulletin. ELECTRICAL SYSTEM; ENGINE. "Start Stop Charging Warning Lamp Illuminated On, Intelligent Battery Sensor (IBS) State of Charge (SOC) Inaccurate, Battery Charging Message, Presence of IBS related Diagnostic Trouble Codes (DTCs), or Battery Warning Lamp On "
9100338REV12024-06-04. Service bulletin. ENGINE. "GENERATOR Engine Prior to alternator/generator removal: 1. Inspect & check all electrical connections to the alternator a. 2-way connector containing field control circuit & alternator sense voltage circuit. b. Unplug & plug-in the 2-way connector for field & sense circuit. Verify the connection is tight & check for any bent pins in alternator connector or damage to female terminals in connector. c. Check Alternator B+ Stud connection to be sure nut is securing positive cable terminal properly (i.e. nut is clamping terminal & connection is tight). d. Check fuse between the alternator B+ stud & PDC terminal to make sure it is not blown. e. Be sure to follow service manual sections on ALTERNATOR CONTROL CIRCUIT DIAGNOSTIC & ALTERNATOR SENSE CIRCUIT DIAGNOSTIC looking for any opens & shorts (to ground or battery voltage). 2. Check/verify all grounds in the charging system circuit a. Check tightness of mounting bolts securing alternator to engine block. Alternator is a case ground component. b. Check main ground from engine to chassis; connection must be tight. c. Check battery ground cable connections are tight. d. Potentially, loosen alternator mounting bolts, without removing alternator, and re-tighten to torque specifications in service manual. e. After all steps above are complete, re-start engine & check charging system operation. 3. Verify that the Smart Charging System is not the reason for alternator low voltage & current output (Amps). a. Alternator charging can be suspended during engine idle operation because of the Smart Charge strategy. b. Refer to service manual section ""System Operation - Smart Charging System"". c. Refer to Star Case S2008000031 Rev A for low charging voltage & Smart Charge Mode Voltage Range diagram & mode descriptions. d. The alternator has no internal regulator; thus, has no smart circuitry. All alternator control signals come from ECM. 4. If alternator is faulty, remove alternator & mounting bolts. Return alternator with bolts for analysis at QEC."
983542024-05-31. Other. ENGINE. Valve - EGR
981712024-05-31. Other. ENGINE; ELECTRICAL SYSTEM. MODULE - ENGINE CONTROLLER
09017232023-10-02. Service bulletin. FUEL SYSTEM, DIESEL; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. Diesel Particulate Filter (DPF) - X97 Warranty Extension Installation of Particulate Matter (PM) sensor.
RecallY432023-10-02. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL. Emission Recall Y43 - Particulate Matter Sensor (Date on document incorrectly states "July 2023")
09013232023-09-25. Service bulletin. ENGINE AND ENGINE COOLING. 6.7L New Oil Usage Information Incorrect oil used. This bulletin provides information regarding the correct oil grade to use on the 6.7L Cummins used in the 2023 to 2013 HD Trucks. The following information is intended to eliminate confusion.
Y432023-09-25. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL. Emissions Recall Y43 Particulate Matter Sensor
S21090000112023-09-25. Service bulletin. ENGINE AND ENGINE COOLING. Squeak, Chirp, Or Tick Noise From The Serpentine Belt Area. Additional Diagnostics.
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.
07007232023-07-31. Service bulletin. ENGINE AND ENGINE COOLING. Water Quality When Mixed With Engine Coolant
18048232023-05-30. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING. wiTECH Small Leak Verification Test (SLVT) - P0456-EVAP SYSTEM SMALL LEAK
S21090000062023-01-17. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:OIL/LUBRICATION:SEALS/GASKETS. Oil Leak From The Oil Pan Gasket.
S21230000552023-01-17. Service bulletin. ENGINE; SERVICE BRAKES. HD Truck Brake Pedal Feel On Gas Engine Equipped
S21090000042023-01-17. Service bulletin. ENGINE AND ENGINE COOLING. Issue involves overheating, running hot, coolant leaks and related symptoms after a Mopar replacement engine has been installed in the vehicle.
Y43 Combo2023-01-17. Service bulletin. ENGINE. Emissions Recall Y43 Particulate Matter Sensor
S22070000032023-01-17. Service bulletin. ENGINE AND ENGINE COOLING; FUEL SYSTEM, GASOLINE. Suspected Internal Exhaust Gas Recirculation (EGR) Cooler Coolant Leak, Additional Diagnostics.
91001122023-01-17. Service bulletin. FUEL SYSTEM, GASOLINE; ENGINE AND ENGINE COOLING. Gasket, Cylinder Head Cover For US dealers, and 21-22 model year vehicles only. If replacing the cylinder head cover/fuel injector harness gasket due to an oil leak, please also replace the following components: 1. 68445548A$ - Cover, Cylinder Head (includes gasket); 2. 05179087A$ - Housing, Rocker Arm; 3. 68005453A$ - Bolt and Grommet, Cylinder Head Cover to Cylinder Head (qty 6); 4. 05114418A$ - Gasket, Rocker Arm Housing; Engineering requires these parts for analysis to determine root cause of the leak. Once the repairs are complete, please contact FCA Redacted Content to set up a Fast Track for the return of the parts.
S2008000186REVA2023-01-09. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM); ELECTRICAL SYSTEM. Engine Control Module (ECM) Flash Failure, Diagnostic Trouble Code (DTC) U1601 ? ECU Application Software Code 1 Missing Or Corrupted
91000212023-01-09. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:CRANK/CAMSHAFT POSITION SENSOR. Seal, Crankshaft Oil, Rear,Retainer, Crankshaft Oil Seal US dealers only: If you are replacing the rear main seal due to an oil leak, do NOT remove the seal from the retainer. Replace the seal and retainer (pn# 05086755A$) as a complete unit. Engineering needs to obtain the seals and retainers back for analysis without them having been disassembled. Once repairs are complete, please contact FCA Redacted Content to return the parts.
822942023-01-09. Service bulletin. FUEL SYSTEM, GASOLINE; ENGINE AND ENGINE COOLING. Warranty Bulletin D-19-02 Fast Feedback Program - 6.7L Cummins Engine & Fuel Injection Pump - 2019 - 2022 HD Ram - All Models (Rev. I)
S22080000732023-01-09. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM). No Start, After Flash And Or PCM Replace, DTC P0513 Invalid Skim Key Setting
S22090000022023-01-09. Service bulletin. ENGINE. Customer complaints may include abnormal engine noise, rough idle, lack of power, misfire. When performing diagnosis, an internal engine concern may be suspected.
S22090000042022-12-19. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING. If a Mopar oil filter is not available, use a filter that meets or exceeds USCAR36 specification and is compatible with semi and full synthetic oils.
90044142022-12-19. Service bulletin. ENGINE AND ENGINE COOLING:COOLING SYSTEM:FAN; FUEL SYSTEM, DIESEL. DRIVE, Fan If a heavy duty diesel vehicle comes in with reports of loud fan noise or fan always on, please call FCA Redacted Content. If no response within 15 minutes, proceed with repair

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