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Service bulletins for the 2020 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.

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

By type

By component

By trouble code

Bulletins, newest first
KC-2229-Ver22023-06-05. Service bulletin. POWER TRAIN. CBR: Automated Manual Transmission (AMT) Transmission Kickdown Mode
KC-474-Ver52023-06-05. Service bulletin. POWER TRAIN. CBR: Diagnostic Trouble Code (DTC) P215A-64, Fault Code SPN 84 FMI 19
KC-2012-Ver32023-06-05. Service bulletin. SERVICE BRAKES. CBR: SNM 20-005 - HD Disc Brake Rotor Upgrade
KC-2263-Ver52023-06-05. Service bulletin. ENGINE AND ENGINE COOLING. CBR: Timing Gear Plate Repair. This solution provides supplementary information to be used when installing a Timing Gear Plate with Integrated Seal.
KC-22642023-05-03. Service bulletin. ELECTRICAL SYSTEM. CBR: Mack Chassis - Allison Reduced Engine Load At A Stop (RELS) Diagnostic Trouble Code P071a Or P07ce - GR,TE,LR Models - Non-Split/Drop Box PTO
KC-22692023-05-02. Service bulletin. ENGINE AND ENGINE COOLING. CBR: 11L Engines, Non-Common Rail - Air Compressor Coolant Pipe, Parts Substitution - US14+OBD13 To US14+OBD16
S76272023-03-07. Service bulletin. ENGINE AND ENGINE COOLING. Mack MMD Alternator Pulley
S75672023-03-07. Service bulletin. ENGINE AND ENGINE COOLING. Electronic Pressure Releif Valve (EPRV) Delete & Fuel Rail Pressure Sensor
KC-22442023-03-07. Service bulletin. STRUCTURE:FRAME AND MEMBERS; SUSPENSION. Mack Model TE,LR - Frame Over Height
KC-21652023-03-07. Service bulletin. ENGINE AND ENGINE COOLING. Mack DEF Pump Troubleshooting Guide - US10+OBD13 And Newer Emissions
M-212-0012023-01-04. Service bulletin. ENGINE AND ENGINE COOLING. Timing Gear Plate Inspection
KC-3282022-12-05. 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
KC-21652022-11-03. Service bulletin. ENGINE AND ENGINE COOLING; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. Mack DEF Pump Troubleshooting Guide - US10+OBD13 And Newer Emissions
M-265-0022022-10-06. Service bulletin. ENGINE AND ENGINE COOLING. TSB-Charge Air Cooler t-clamp install.
KC-22132022-10-04. Service bulletin. ELECTRICAL SYSTEM. Mack Chassis - Malfunction Indicator Light (MIL) Illuminated After Start Up - Cummins CNG Only
KC-21392022-09-07. Service bulletin. ENGINE AND ENGINE COOLING; FUEL SYSTEM, DIESEL. fuel in the oil inspection
KC-7332022-07-05. Service bulletin. ENGINE AND ENGINE COOLING. Back Office Mack Chassis - Secondary Gauge Set Up - Model Year 2018 and Newer.
KC-21072022-07-05. Service bulletin. ENGINE AND ENGINE COOLING. DEF Level (UQLS) Sensor Troubleshooting Guide - US17+OBD16 Emissions and Newer.
KC-21122022-07-05. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN; ENGINE AND ENGINE COOLING. Programming Failure - Chassis With Cummins Engine And An Allison Transmission
KC-21162022-07-05. Service bulletin. ENGINE AND ENGINE COOLING. NOx Sensor Troubleshooting Guide - US10+OBD13 And Newer Emissions.
KC-21432022-07-05. Service bulletin. VEHICLE SPEED CONTROL. (Back Office) - Cruise Control Inoperative After Updating Software VECU5 Without ESP Package (UESP).
KC-21572022-07-05. Service bulletin. ENGINE AND ENGINE COOLING; FUEL SYSTEM, GASOLINE. Aftertreatment Hydrocarbon Injector (AHI) Troubleshooting Guide - US10+OBD13 And Newer Emissions.
KC-21582022-07-05. Service bulletin. ENGINE AND ENGINE COOLING. Selective Catalytic Reduction (SCR) Muffler Troubleshooting Guide - US10+OBD13 And Newer Emissions.
KC-21652022-07-05. Service bulletin. ENGINE AND ENGINE COOLING. DEF Pump Troubleshooting Guide - US10+OBD13 And Newer Emissions.
KC-3992022-07-05. Service bulletin. ELECTRICAL SYSTEM. Vehicle Overspeed Warning Comes Active At A Lower Speed Than Expected; Vehicle Overspeed Warning In Driver Information Display (DID) - Model Year 2018 And Newer With New Style Instrument Cluster.

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