WenmarOpen by Wenmar Pro

Service bulletins for the 2023 Peterbilt 579

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.

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

By type

By component

By topic

Only bulletins with component: Engine are shown. Show all

Bulletins, newest first
E3272025-03-04. Emissions. ELECTRICAL SYSTEM; ENGINE. "Vehicles equipped with PACCAR MX engines with Engine Software Version NA202 or NA206 may display a dash STOP lamp incorrectly. PCI-2 software on these chassis must be reverted from NA202 to NA201 (Pack 2 injectors) or from NA206 to NA191 (Pack 1 injectors) to prevent incorrect STOP lamp display.
32-0252024-12-03. Service bulletin. ENGINE. Info Only Unnecessary starter replacements can result from customer complaints regarding engine starting issues. A new Starter Troubleshooting Guide has been created to provide a comprehensive list of starting system checks, which should reduce unnecessary starter replacements and associated warranty claims. Engine starting system warranty claims now require a completed Starter Checklist, a Battery Pack Midtronics Report, and a Cable Drop Midtronics Report. Claims filed without these documents may be denied.
E3162024-09-10. Service bulletin. ENGINE. Bulletin updated to include oil pan drain plug in parts list and incorporated QR code to direct dealers to informational resources for new Programmable Torque Tool.
E3072024-05-04. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. CARB Emission s Manufacturer Warranty term and/or kilometers conversion displayed in certain EMY 2022-2023 PX-7 or PX-9 Operator’s Manuals are incorrect.
E2902023-12-02. Service bulletin. ENGINE AND ENGINE COOLING. Updated procedures and SRT time to include Fuel Filter replacement during cleaning process. Removed in-tank additive references.
45-0652023-11-10. Service bulletin. ENGINE AND ENGINE COOLING; POWER TRAIN. Certain 579 MLU chassis equipped with Cummins X15 engines have fan hub bracket hardware that are incorrect for the application and/or under torqued and could become loose and/or fail. Procedures are available to replace and properly torque the hardware.
45-0662023-11-10. Service bulletin. ENGINE AND ENGINE COOLING. A testing procedure has been created for the coolant level sensor on model 520.
45-0652023-10-03. Service bulletin. ENGINE AND ENGINE COOLING; POWER TRAIN. Certain 579 MLU chassis equipped with Cummins X15 engines have fan hub bracket hardware that are incorrect for the application and/or under torqued and could become loose and/or fail. Procedures are available to replace and properly torque the hardware.
01-0792023-07-05. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM; VISIBILITY; ENGINE AND ENGINE COOLING. Fix-as-Fail - HVAC Intermittently Stops Blowing Cold Air
E3002023-05-05. Service bulletin. ENGINE AND ENGINE COOLING. PACCAR will reimburse customers for the local purchase of in-tank fuel additive for EPA2021 compliant MX engines. This is a one-time reimbursement. Only customers who have received E290 injector cleaning qualify for this reimbursement. See bulletin for limits and purchase tracking requirements.
E2902023-05-05. Service bulletin. ENGINE AND ENGINE COOLING. FIX-AS-FAIL – Updated procedures and claim filing information. EPA2021 injector cleaning is referenced in RMI for certain injector faults. Complete the procedures in E290. Refer to E300 for in-tank additive information.
03-087(E295)2023-03-01. Service bulletin. ENGINE AND ENGINE COOLING. Certain Model Year 2021-2024 chassis with PACCAR MX engines and optional fuel filter restriction virtual gauge may display incorrect restriction levels. The virtual gauge will be temporarily disabled until are vised sensor strategy is developed.
R22022023-02-06. Service bulletin. ENGINE AND ENGINE COOLING. The emissions exemption expired on 12/31/2022 for certain pre-production vehicles equipped with PACCAR Model Year 2023 MX engines. Production-level engine, VECU, and Digital Display software is now available to make these vehicles compliant. New Engine Emissions and Clean Idle labels will be installed.
45-0642022-11-02. Service bulletin. ENGINE AND ENGINE COOLING. Info Only - PACCAR is introducing Over-the-Air (OTA) software updates for engine MY17 and newer chassis equipped with Cummins X15, X12, ISX12, ISX12N, L9N, PX-7, and PX-9 engines The technology will leverage the existing Remote Diagnostic cs hardware to deliver secure software updates remotely. This will reduce downtime and save on maintenance costs for eligible vehicles.

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