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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

Bulletins, newest first
KC-6442022-06-07. Service bulletin. ENGINE AND ENGINE COOLING. Manual Compression Test Adapter For Engines With Stainless Steel Injector Sleeves (Conical Tip Injectors) - US07 And Newer Emissions, Model Year 2008 And Newer
KC-6272022-06-07. Service bulletin. EQUIPMENT. Premium Tech Tool ( PTT ) Training Materials And Support Tools
KC-21722022-06-07. Service bulletin. UNKNOWN OR OTHER; ELECTRICAL SYSTEM. No Start Condition After Over The Air Programing - VECU5 No Start "Safe State"
KC-21712022-06-07. Service bulletin. ENGINE AND ENGINE COOLING. Temperature Sensor Troubleshooting Guide - US10+OBD13 And Newer
KC-21702022-06-07. Service bulletin. SUSPENSION. Electronically Controlled Suspension (ECS) Losing Air Pressure
KC-21692022-06-07. Service bulletin. ELECTRICAL SYSTEM. Low Voltage Disconnect (LVD), Function Description
KC-21652022-06-07. Service bulletin. ENGINE AND ENGINE COOLING. DEF Pump Troubleshooting Guide - US10+OBD13 And Newer Emissions
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-6262022-06-07. Service bulletin. POWER TRAIN. Mack Chassis - Vehicles Equipped With An Automated Manual Transmission Model F ( AMT-F, mDrive ), Premium Tech Tool ( PTT ) Gearbox Calibration Failure; Gearbox Calibration Operation Stops And Fails At 33% When Run With Transmission Removed
KC-6332022-06-07. Service bulletin. WHEELS. Mack Chassis - Front Hub With Unit-Bearings ( Unitized Wheel Bearings ), Inspection Information And Guidelines - Commonly Model Year 2008 And Newer
KC-6482022-06-07. Service bulletin. UNKNOWN OR OTHER; POWER TRAIN. Mack - PTO Pump Speed Calculator
KC-6512022-06-07. Service bulletin. EQUIPMENT. Mack Dealer Support Communication - Selecting The Proper SR Area For Creating An eService
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-6862022-06-07. Service bulletin. VEHICLE SPEED CONTROL; ELECTRONIC STABILITY CONTROL:AUTOMATIC (ASC). (Back Office Only) Mack Chassis - Cruise Control Inoperative After Disabling The Electronic Stability Program (ESP)
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-6992022-06-07. Service bulletin. ELECTRICAL SYSTEM. Mack Chassis - Bendix Vendor Configuration Program ( VCP ) Software Download Information
KC-7002022-06-07. Service bulletin. POWER TRAIN. Mack Chassis - Automated Manual Transmission Model F ( AMT-F, mDrive ) - Short Transmission Replacement; Calibration And/Or Shifting Problems Following Replacement Of A Short Transmission - US17+OBD2016 And Newer Emissions, Model Year 2018 And Newer
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-7312022-06-07. Service bulletin. POWER TRAIN. Mack Chassis - Equipped With An Automated Manual Transmission Model D or F (mDrive, AMT-D, AMT-F) - Transmission Oil Leakage From Transmission Input Shaft Seal Or Output Shaft Seal - US10 And Newer Emissions, Common Model Years 2010 And Newer
KC-5872022-06-07. Service bulletin. ENGINE AND ENGINE COOLING; ENGINE. Mack Chassis - SNM15-027 A/C Compressor Inspection Required For Warranty Repairs

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