WenmarOpen by Wenmar Pro

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
SNM21-0012021-02-01. Service bulletin. ENGINE AND ENGINE COOLING. Improved method for determining which DTC to troubleshoot in a MIL on situation
FSB 284-0702021-01-07. Service bulletin. FUEL SYSTEM, DIESEL; ELECTRICAL SYSTEM:WIRING; EQUIPMENT. DTC P0194-00 and/or P016E-00, Fuel Rail Pressure Sensor (RPS) and wiring harness, Replacement
FSB 810-0042020-08-05. Service bulletin. STRUCTURE. Back of Cab Crack, Repair
K533380752020-06-03. Service bulletin. ENGINE AND ENGINE COOLING. Diagnostic Trouble Codes (DTC) For The Engine Pre-Heat Relay: Supplementary Instructions - US10+OBD13 And Newer Emissions, Model Year 2014 And Newer
FSB 386-0112020-06-03. Service bulletin. EQUIPMENT:ELECTRICAL; SERVICE BRAKES, AIR:SUPPLY:LOW PRESSURE WARNING:SWITCH. Air Pressure Switch, Replacement
K475478562020-05-06. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT. Particulate Matter (PM) Sensor Diagnostic Trouble Codes (DTC) Illuminating The Malfunction Indicator Lamp (MIL) - US14+OBD16, US17+OBD16 And Newer Emissions, Model Year 2017 And Newer - To Be Used For EVERY Visit
K595542552020-05-05. Service bulletin. ENGINE AND ENGINE COOLING. EXPIRED - Refer To K47547856 - Debranded Solutions - Mack Chassis - Particulate Matter (PM) Sensor Diagnostic Trouble Codes (DTC) Illuminating The Malfunction Indicator Lamp (MIL); Tech Tip TT-014-2016 - US14+OBD16, US17+OBD16 And Newer Emissions, Common Model Year 2017 And Newer - To Be Used For EVERY Visit
FSB 233-0072020-05-05. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; FUEL SYSTEM, DIESEL. Fuel Filter Housing, Replacement
K011572832020-04-06. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:GASOLINE:BELTS AND ASSOCIATED PULLEYS; ELECTRICAL SYSTEM. Front Accessory Drive Noise, Alternator Belt Wear, Alternator Belt Tensioner Failure - Model Year 2017 And Newer
K011572832020-04-03. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING:ENGINE:GASOLINE:BELTS AND ASSOCIATED PULLEYS; ELECTRICAL SYSTEM. Front Accessory Drive Noise, Alternator Belt Wear, Alternator Belt Tensioner Failure - Model Year 2017 And Newer
S74612020-04-02. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY. LR OBD CONNECTOR CORROSION FOR DSNY KNEE BOLSTER
S74542020-03-09. Service bulletin. ENGINE. Modify Air Dryer TCOV
K535805142020-01-13. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; ENGINE. Brake Drum Inspection - Checking Runout, Wear, And Other Characteristics
K318223252020-01-13. Service bulletin. POWER TRAIN; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT. Mack Chassis - Differential Carrier Models CRD 125 And CRD 150 - New Differential Axle Seal Installation Tool; New Tool Required For New Input And Output Seal Installation
K250360452020-01-13. Service bulletin. EQUIPMENT; ENGINE. Mack Chassis - Diagnostic Trouble Code ( DTC ) SPN4094, Check List - US10 Emissions
K409142412020-01-13. Service bulletin. FUEL SYSTEM, GASOLINE. Common Rail Fuel System Faults - Diagnostic Trouble Codes (DTC) P0094, P228F, P016F, P0087,P00C6, P0257, P2A17, P2A1F, P008A; Repair Information - US17+OBD16, US17+OBD18, and US17+OBD19 Emissions, Model Years 2018 To 2020
K292957442020-01-13. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; ENGINE AND ENGINE COOLING:ENGINE:DIESEL; EQUIPMENT. Updated PM Sensor Removal Procedure - US17+OBD16 and Newer Emissions
K889928922020-01-13. Service bulletin. FUEL SYSTEM, GASOLINE; ENGINE; EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY. Assembled Camshaft - Injector Lobe Rotation Inspection For Possible Spun Camshaft Lobe; Diagnostic Trouble Codes (DTC) P0257-00, P2A17-00, Or P2A1F-00, Possible Lack Of Power - US17+OBD16 and Newer Emissions
K208781182019-12-09. Service bulletin. EQUIPMENT. Diagnostic Trouble Codes ( DTC ) P205B-64 - Reductant Tank Temperature Sensor Circuit Range/Performance - Model Year 2018 and Newer
K300241432019-10-28. Service bulletin. ENGINE AND ENGINE COOLING. Mack Chassis - Oil Diluted With Fuel; Fuel In Oil, Diagnostic Information - All Emissions Prior To US17+OBD16 (Common Rail Fuel System), Model Year 2017 And Older
K595542552019-09-30. Service bulletin. EXTERIOR LIGHTING; BACK OVER PREVENTION. Mack Chassis - Particulate Matter (PM) Sensor Diagnostic Trouble Codes (DTC) Illuminating The Malfunction Indicator Lamp (MIL); Tech Tip TT-014-2016 - US14+OBD16, US17+OBD16 And Newer Emissions, Common Model Year 2017 And Newer - To Be Used For EVERY Visit
K655277082019-08-19. Service bulletin. EQUIPMENT. Diagnostic Trouble Codes (DTC) P20EE And P103C, Diagnostic Procedure; REPLACES GUIDED DIAGNOSTICS IN PREMIUM TECH TOOL ( PTT ) - US17+OBD16 And Newer Chassis ONLY
K595542552019-07-15. Service bulletin. EQUIPMENT. Mack Chassis - Particulate Matter (PM) Sensor Diagnostic Trouble Codes (DTC) Illuminating The Malfunction Indicator Lamp (MIL); Tech Tip TT-014-2016 - US14+OBD16, US17+OBD16 And Newer Emissions, Common Model Year 2017 And Newer - To Be Used For EVERY Visit
k230235452019-07-15. Service bulletin. EQUIPMENT. Wabco System Saver? HP High Performance Air Dryer - US17 +OBD2019 Emissions, Model Year 2020
K869000432019-07-15. Service bulletin. ENGINE AND ENGINE COOLING. Exhaust Gas Recirculation (EGR) System - Fault Codes SPN 412 FMI 0,2,5; Diagnostic Trouble Codes (DTC) P040A, P040B, P1121 - Temperature Sensor Inspection

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