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Service bulletins for the 2021 Mack MD

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.

112 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
KC-21612022-06-07. Service bulletin. ENGINE AND ENGINE COOLING. DEF Pump Cycling periodically Hours After Key Off
KC-21582022-06-07. Service bulletin. ENGINE AND ENGINE COOLING. Selective Catalytic Reduction (SCR) Muffler Troubleshooting Guide - US10+OBD13 And Newer Emissions
KC-21572022-06-07. Service bulletin. ENGINE AND ENGINE COOLING. Aftertreatment Hydrocarbon Injector (AHI) Troubleshooting Guide - US10+OBD13 And Newer Emissions
KC-21312022-06-07. Service bulletin. ENGINE AND ENGINE COOLING. USE FOR NEW VEHICLES (US21+OBD22 Emissions) - Intermittent Diagnostic Trouble Codes U02A3, U029D, U029E
KC-21162022-06-07. Service bulletin. ENGINE AND ENGINE COOLING. NOx Sensor Troubleshooting Guide - US10+OBD13 And Newer Emissions
KC-6522022-06-07. Service bulletin. ENGINE AND ENGINE COOLING. Mack Low Oil Pressure Diagnostic Process For 11 Liter Engines
KC-6592022-06-07. Service bulletin. ENGINE AND ENGINE COOLING; FUEL SYSTEM, DIESEL. Mack Chassis - Oil Diluted With Fuel; Fuel In Oil, Diagnostic Information - All Emissions Prior To US17+OBD16 (Common Rail Fuel System), Model Year 2017 And Older
KC-6982022-06-07. Service bulletin. ENGINE AND ENGINE COOLING. Mack Chassis - Diesel Exhaust Fluid ( DEF ) System Cleaning/Flush After DEF Pump Failure Or System Contamination
KC-7142022-06-07. Service bulletin. ENGINE AND ENGINE COOLING. Mack Chassis - Diagnostic Trouble Codes ( DTC's ) - P020113, P020213, P020313, P020413, P020513, P020613, Cylinders 1 Through 6 Injector A Open Circuit
KC-5872022-06-07. Service bulletin. ENGINE AND ENGINE COOLING; ENGINE. Mack Chassis - SNM15-027 A/C Compressor Inspection Required For Warranty Repairs
M-261-0012022-06-06. Service bulletin. ENGINE AND ENGINE COOLING. Fitting, Static Hose Fill, Replacement
KC-21662022-04-06. Service bulletin. ENGINE AND ENGINE COOLING. Mack MMD Models - Coolant Hose Obstructs Access To Oil Filter
KC-21072022-03-03. Service bulletin. ENGINE AND ENGINE COOLING. DEF Level (UQLS) Sensor Troubleshooting Guide - US17+OBD16 Emissions and Newer
KC-5612022-03-03. Service bulletin. ENGINE AND ENGINE COOLING. Engine Oil Analysis Specifications - US10 And Newer Emissions
KC-5522022-03-03. Service bulletin. ENGINE AND ENGINE COOLING. Aftertreatment Control Module ( ACM ) Diagnostic Trouble Codes ( DTC ) U0001-88 and U0010-88 Lighting The Malfunction Indicator Lamp ( MIL ); Possible Derate Warning – US10 And Newer Chassis
KC-21072022-03-03. Service bulletin. UNKNOWN OR OTHER; ENGINE AND ENGINE COOLING. DEF Level (UQLS) Sensor Troubleshooting Guide - US17+OBD16 Emissions and Newer
KC-4782022-02-06. Service bulletin. ENGINE AND ENGINE COOLING. Variable Geometry Turbocharger ( VGT ) Function Test ( 2551-08-03-02 ), OBD13 Model Year ( MY ) 2014 And Newer
KC-4152022-02-04. Service bulletin. ENGINE AND ENGINE COOLING. Diagnostic Trouble Code ( DTC ) P26E8 Intermittently Lighting The Malfunction Indicator Lamp ( MIL ); Possible Derate Warning - US10+OBD13 And Newer Emissions, Model Year 2014 And Newer
KC-4012022-02-04. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL. Diagnostic Trouble Codes (DTC) P24F600 Or P24F700 - US14+OBD15 Emissions And Newer, Model Year 2016 And Newer
KC-4022022-02-04. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL; ELECTRICAL SYSTEM. Volvo Chassis - Diagnostic Trouble Code (DTC) SA 0 FMI 0 or SPN 0 FMI 0 Present On Fault Code Readout - US10 And Newer Emissions, Model Year 2011 And Newer
KC-20432022-01-08. Service bulletin. ENGINE AND ENGINE COOLING; ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM):SOFTWARE; ELECTRICAL SYSTEM:SOFTWARE. Engine Control Module (EMS) Software (MSW) Information - Improvement List, November 2021 - US21+OBD2020 Emissions
GDC21-0112022-01-07. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:OIL/LUBRICATION:PRESSURE/TEMPERATURE SENSOR; ENGINE AND ENGINE COOLING. Exhaust Gas Temperature Sensor Circuit Range/Performance
KC-2752022-01-06. Service bulletin. ENGINE AND ENGINE COOLING. (Back Office Only) Vehicles Equipped With A Turbo Compound Engine - Report Of Frequent Air Compressor Cycling. Secondary Air System Air Pressure Decreases Slowly When Engine Is At Low Idle - US17+OBD16 And Newer Emissions, Model Year 2018 And Newer
KC-2382022-01-06. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL. Mack Chassis - Where To Find The Body Builder Portal - Body Builder Manual ( BBM ) Information - US04 And Newer Emissions, Model Year 2008 And Newer
KC-1932021-12-07. Service bulletin. ENGINE AND ENGINE COOLING. Mack Chassis - Particulate Matter (PM) Sensor Diagnostic Trouble Codes (DTC) Illuminating The Malfunction Indicator Lamp (MIL); Tech Tip TT-014-2016 - US14+OBD16, US17+OBD16 And Newer Emissions, Common Model Year 2017 And Newer - To Be Used For EVERY

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