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Service bulletins for the 2020 Mack Anthem

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.

269 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

Bulletins, newest first
M0039 0320262026-04-02. Emissions. ENGINE. Emissions - EC0039 MST21 Failure to Detect P20EE - AN, CHU.
CBR 2107-22 2026012026-02-02. Service bulletin. ENGINE. CBR - Mack DEF Level (UQLS) Sensor Troubleshooting Guide - US17+OBD16 Emissions to US22+OBD2023 (DOES NOT APPLY TO AN(4) and PR(4)).
CBR 199 2025122026-01-05. Service bulletin. ENGINE. Vehicles affected by this issue will show coolant runoff on the front rights side of the engine.
CBR 2171-11 2025112025-12-03. Service bulletin. ENGINE; ELECTRICAL SYSTEM. CBR - Mack Temperature Sensor Troubleshooting Guide
CBR 199-6 2025112025-12-03. Service bulletin. ENGINE. CBR - 13 Liter Engines ONLY - Engine Coolant Pump Housing Leak; Coolant Found Around The Oil Cooler Duct Cover Or In Between The Coolant Pump Housing And Oil Cooler Housing.
CBR 2107-21 2025052025-06-02. Service bulletin. FUEL/PROPULSION SYSTEM; ENGINE. Mack DEF Level (UQLS) Sensor Troubleshooting Guide - US17+OBD16 Emissions and Newer
CBR 170-8 2025052025-06-02. Service bulletin. ENGINE. Inactive Code P25AE00 Being Generated After A Hard Pull And A Momentary Drop In Engine Oil Pressure (Low Oil Pressure) (Possible Related Codes - SPN4811 , SPN 100 , PID 100)
CBR-2449 2025032025-04-02. Service bulletin. ENGINE. Cummins Exhaust Aftertreatment System (EATS) catalysts may experience cracking, which may be attributed to excessive vertical vibration in the exhaust stack. To mitigate this issue, a modification to the exhaust stack length is required.
CBR-561 2025032025-04-02. Service bulletin. ENGINE. If oil dilution is suspected refer to the applicable CBR solution below: ∙ CBR-659􀁡Mack Chassis - Oil Diluted With Fuel; Fuel In Oil, Diagnostic Information - All Emissions, All Model Years
CBR-997 2024112024-12-02. Service bulletin. ENGINE. Vehicles may present with oil leak coming from the clutch/flywheel housing and observation of burned clutch smell or clutch slipping. These symptoms can be mistaken as a crankshaft rear main seal leak, when the actual cause is the crankshaft adaptor O-ring.
CBR-2263 2024102024-11-04. Service bulletin. ENGINE. CBR - Mack Chassis - Timing Gear Plate Repair
M0311 2024092024-10-04. Emissions. ENGINE. Emission Recall: EC0033-M0311 SCR Recall
M0304 2024092024-10-04. Emissions. ENGINE. Emission Recall: EC0033-M0304 SCR Recall
CBR-561 2024082024-09-04. Service bulletin. ENGINE. CBR: 11L, 13L, And 16L Engine Oil Analysis Specifications - US10 And Newer Emissions
CBR-523 2024082024-09-04. Service bulletin. ENGINE. CBR: Overhead Wear Overview - Model Year2018 To Current (Common Rail Fuel System ONLY)
CBR-2139 2024052024-06-04. Service bulletin. FUEL/PROPULSION SYSTEM; ENGINE. CBR: Vehicles built with an 11 liter engine may experience a complaint of excessive fuel in the oil. It is possible that the source of the fuel is the rear fuel galley plug in the cylinder head. A new and improved fuel galley plug has been developed to resolve this issue.
CBR-2214 2024042024-05-01. Service bulletin. ENGINE AND ENGINE COOLING. CBR: Turbo Compound 2nd Generation - EGR And / Or DPF Diagnostic Trouble Codes (DTC), Diagnostic And Repair Information.
CBR-2013 2024042024-05-01. Service bulletin. ENGINE AND ENGINE COOLING. CBR: Turbo Compound (TC) Hot Side Noise, Diagnostic Information.
CBR-2139 2024032024-04-02. Service bulletin. ENGINE AND ENGINE COOLING. CBR: Vehicles built with an 11 liter engine may experience a complaint of excessive fuel in the oil. It is possible that the source of the fuel is the rear fuel galley plug in the cylinder head.
S2964 2023122024-01-03. Service bulletin. ENGINE AND ENGINE COOLING. Service Campaign: Mack trucks has determined that certain AN model trucks built with an MP8 Turbo Compound engine that have had a reman TC unit installed could experience a failure with the reman TC unit.
CBR-2320 2023122024-01-03. Service bulletin. ENGINE AND ENGINE COOLING. CBR: For vehicles equipped with an 11L engine, the plastic saddle bracket holding the a/c line on the left side of the engine may move excessively and rub the area where it secures the line.
CBR-206 2023102023-11-03. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL. CBR: Vehicle Speed Factor (K-Factor) Programming - Speed Factor Value Incorrect When Calculated In Premium Tech Tool (PTT); Speedometer Reading Incorrectly Following A Change To Vehicle Speed Factor - US17+OBD16 And Newer Emissions, Common Model Year 2018.
U114 2023092023-10-04. Service bulletin. ENGINE AND ENGINE COOLING. Owner Notification Letter, Extended Warranty Coverage U114. The EGR Cooler is the component provided coverage under this warranty extension.
M-258-014 2023092023-10-03. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:DIESEL; ENGINE AND ENGINE COOLING. TSB: Aftertreatment Diesel Exhaust Fluid (DEF) Tank, Level Sensor, Replacement
M-141-001 2023082023-09-06. Service bulletin. ENGINE AND ENGINE COOLING. TSB: Air Restriction Indicator

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