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
| KC-167 | 2021-12-07. Service bulletin. ENGINE AND ENGINE COOLING. Premium Tech Tool (PTT) Error Code 43: Service Regeneration Fails To Start; Service Regen Does Not Complete With Error 43 Displayed - US10+OBD13 And Newer Emissions, Common Model Year 2014 And Newer |
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| KC-159 | 2021-12-07. 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-136 | 2021-11-05. 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-130 | 2021-11-05. 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 |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.