WenmarOpen by Wenmar Pro

Service bulletins for the 2021 Mack LR

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.

163 on file from NHTSA, as of 2026-10-19.

By type

By component

By trouble code

Only bulletins with component: Engine control module are shown. Show all

Bulletins, newest first
KC-2043 Rev 42023-07-06. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM); ELECTRICAL SYSTEM. Engine Control Module (EMS) Software (MSW) Information - Improvement List, Through June 2023 - US21+OBD2020 Emissions
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
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

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