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Service bulletins for the 2020 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.

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

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Only bulletins with component: Engine are shown. Show all

Bulletins, newest first
P0012026-09-29. Service bulletin. ENGINE. "Kenworth: Dealers should check the chassis list and SIR weekly for VIN changes. 2 chassis added to the chassis list. Peterbilt: Dealers should check the chassis list and SIR weekly for VIN changes. 10 chassis added to the chassis list."
E3432026-09-23. Service bulletin. ENGINE. An exhaust manifold slip joint seal kit is now available for EPA 2017-2024 PACCAR MX-13 engines.
43-0882026-08-20. Service bulletin. ENGINE. The procedure has been updated to include additional steps for verifying the software level on the vehicle electronic control unit (VECU2) and digital display (DD). Steps have also been added to the PACCAR Common Rail Injection 2 (PCI2) software verification.
E3112026-07-30. Service bulletin. ENGINE. 105 chassis have been removed from the chassis list and unflagged in PRWS due to expiration of applicable warranty coverage. Total chassis population is 732.
43-0882026-07-23. Service bulletin. ENGINE. This optional software update is now available for chassis equipped with EMY 2021B-2023 PACCAR MX-11 and MX-13 engines. This update provides customers with additional time to service their trucks before a DEF-related derate occurs. The software is being offered to customers in alignment with recently updated regulatory agency guidance.
41-0292026-07-22. Service bulletin. ENGINE. Incorrect air filters may be inadvertently installed in certain chassis equipped with under-hood Donaldson air filter housings.
E3112026-07-21. Service bulletin. ENGINE. The Condition, Chassis Affected, Service Action, Warranty, and Procedure sections have been updated to include the latest prognostics bulletin verbiage.
43-0882026-07-21. Service bulletin. ENGINE. "The software is not yet available. The bulletin will be updated when more information is available."
43-0882026-07-02. Service bulletin. ENGINE. "An optional software update will be available on 07/06/2026 for chassis equipped with EMY 2021B-2023PACCAR MX-11 and MX-13 engines. This update provides customers with additional time to service theirtrucks before a DEF-related derate occurs. The software is being offered to customers in alignment withrecently updated regulatory agency guidance."
41-0242026-05-20. Service bulletin. ENGINE. Procedures have been updated to include additional truck models in the service intervals table.
42-0642026-05-06. Service bulletin. ENGINE. Fix-as-Fail On certain Kenworth T680 chassis equipped with PACCAR MX-13 engines, wiring to the Horton LCX230 crank-mounted fan drive may experience a short due to chafing or water ingress, affecting fan drive operation.
45-0702026-05-06. Service bulletin. ENGINE. The attached procedures document has been updated with more detail and explanations. This is not a stand-alone procedure. Cummins Quickserve troubleshooting will specify the use of these procedures while troubleshooting specific fault codes.
E3262026-05-06. Emissions. ENGINE; ELECTRICAL SYSTEM. EPA17-24 MX Fuel Injector Connector - This bulletin has been revised to include all EPA17-24 and CARB24 PACCAR MX engines.
41-0242026-04-07. Service bulletin. ENGINE. Engine Air Filter Servicing UPDATE - Procedures are available to support the maintenance, service intervals, and intake system inspection process for all engine air intake system components.
45-0702026-02-05. Service bulletin. ENGINE. Procedure pictures updated for clarity. When troubleshooting Cummins X15 fault codes 555 or 556, follow this additional testing, inspection, and documentation procedure to help identify the root cause of dusted engines. This is not a stand-alone process but must be used alongside Cummins troubleshooting steps. Cummins Quickserve will reference this bulletin for fault codes 555 or 556.
E3112025-09-03. Other. ENGINE; POWER TRAIN. Condition, Chassis Affected, and Warranty sections updated with the following verbiage “E311 must be flagged and open in Service Information Record (SIR) at the time of RO open date to qualify.” Also, “Through Standard Warranty or any applicable active Extended Warranty” verbiage was removed from Warranty section.
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.
7-7002024-11-05. Warranty extension. POWER TRAIN; ENGINE. 7/700 Service Agreement - Letter Only.
E2732023-12-02. Service bulletin. ENGINE AND ENGINE COOLING. Fix As Fail Updated: Two part numbers added: 1818119 DPF Delta Pressure Sensors for MX-13-2 EMY18 2200138 DPF Delta Pressure Sensors for MX-13 -2, EMY19 Per Environment and Climate Change Canada (ECCC) regulations and guidance (Canadian Environmental Protection Act, 1999 (CEPA)), a letter has been provided to owners of Canadian registered chassis that provides a list of emissions components that have been reported (to ECCC) as having a defect.
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
E3032023-02-06. Service bulletin. ENGINE AND ENGINE COOLING. This campaign is the final opportunity to replace the oil filter screw cap to reduce occurrences of broken bypass valve tabs. Broken oil valve tabs can cause oil flow obstruction to critical engine parts, resulting in serious engine damage. Customers that do not receive this repair may be responsible for progressive engine damage caused by broken oil bypass valve tabs.
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.
41-0202022-03-04. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING. The Turbo Inlet Elbow is susceptible to tearing, potentially allowing dust to enter the engine. The Turbo Inlet Elbow will be replaced with an improved part.

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