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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-1632021-12-07. Service bulletin. FUEL SYSTEM, DIESEL. Diesel Fuel Information - Acceptable Biodiesel, Fuel Blend For Summer And Winter - US07 And Newer Emissions, Model Year 2008 And Newer
KC-1592021-12-07. Service bulletin. ENGINE AND ENGINE COOLING. Trucks Equipped With A Cummins Engine - Engine Preheat Icon Does Not Illuminate In The Instrument Cluster (IC) During Engine Pre-heat (Intake Air Heater) Operation - Vehicles With 2018 Instrument Cluster Update, Model Year 2018 And Newer
KC-1452021-12-07. Service bulletin. POWER TRAIN. Automated Manual Transmission (AMT) (Spigot Bearing) Input Shaft Repair Kit And Shim Kit, Part Number Information, Reference Guide - US07 And Newer Emissions, Model Year 2008 And Newer
KC-1192021-12-07. Service bulletin. POWER TRAIN. Mack Chassis - Equipped With An Automated Manual Transmission (mDrive, AMT) AMT-C, AMT-D Or AMT-F - Transmission Oil Specifications - Model Years 2010 To 2020
KC-1362021-11-05. Service bulletin. ENGINE AND ENGINE COOLING. Aftertreatment Control Module (ACM) Offline/Not Visible/Missing From Control Unit Information in Premium Tech Tool (PTT) - US10+OBD13 And Newer Emissions
KC-1302021-11-05. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM); FUEL SYSTEM, OTHER. Air In The Fuel System Tests, Common Rail Fuel System - US17+OBD16 and Newer Emissions
KC-1242021-11-05. Service bulletin. POWER TRAIN. Automated Manual Transmission Gearbox Will Not Shift To High Range After Gearbox Repair; MID 130 PSID 24 FMI 1, P1072-92 Unintentional Disengagement Of High Range - US07 And Newer Emissions, Model Year 2008 And Newer
KC-1152021-11-05. Service bulletin. POWER TRAIN; POWER TRAIN:AUTOMATIC TRANSMISSION:INTERNAL:GEARS. Automated Manual Transmission ( AMT ) ( I-Shift, mDRIVE ) Equipped Chassis, OBD13 And Newer - Light Turbo Surge ( Chuff ) During Skip Shifting
SNM21-0062021-11-04. Service bulletin. COMMUNICATION:MANUFACTURER TELEMATICS; UNKNOWN OR OTHER; ELECTRICAL SYSTEM:SOFTWARE. Remote Software Downloads
KC-3282021-10-01. Service bulletin. ELECTRICAL SYSTEM. Diagnostic Trouble Codes (DTC) P208064, P208464, P242B64 and P246F64 Lighting The Malfunction Indicator Lamp (MIL) - US17+OBD19 And Newer Emissions, Model Years 2020 and Newer
S75882021-08-02. Service bulletin. EQUIPMENT. Mack Medium Duty Refrigerant Label Replacement
S75902021-07-06. Service bulletin. SUSPENSION. MMD - Carrier Bearing Bolt Re-Torque

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