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Service bulletins for the 2024 Peterbilt 520

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.

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

By type

By component

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."
P0022026-09-23. Service bulletin. ENGINE. "KW: A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section. PB: The chassis list has been updated to include 2 chassis. The total chassis count is now 4. A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section."
P0022026-08-27. Service bulletin. ENGINE. "KW: A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section. PB: The chassis list has been updated to include 2 chassis. The total chassis count is now 4. A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section."
43-0892026-08-25. Service bulletin. ENGINE. This optional software update is expected to be available after 08/28/2026.
P0012026-08-20. Service bulletin. ELECTRICAL SYSTEM; ENGINE. Chassis list has been updated to include 10 chassis. The total chassis count is now 101.
43-0892026-08-20. Service bulletin. ENGINE. This optional software update is expected to be available in late August 2026 for chassis equipped with EPA 2024 EMY 2024-2026 PACCAR MX-11 and MX-13 engines. This bulletin will be updated when the software is ready. 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. The procedure document has also been updated for clarity.
43-0892026-08-20. Service bulletin. ENGINE. This optional software update is expected to be available in late August 2026 for chassis equipped with EPA 2024 EMY 2024-2026 PACCAR MX-11 and MX-13 engines. This bulletin will be updated when the software is ready. 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. The procedure document has also been updated for clarity.
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.
43-0892026-08-01. Service bulletin. ENGINE. This optional software update is expected to be available on 08/07/26 for chassis equipped with EPA 2024 EMY 2024-2026 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.
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.
43-0892026-07-22. Service bulletin. ENGINE; ELECTRICAL SYSTEM. An optional software update is expected to be available on or after 07/31/26 for chassis equipped with EPA 2024 engine model year (EMY) 2024-2026 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.
E3182026-07-22. Service bulletin. ENGINE. The Condition, Chassis Affected, Service Action, Warranty, and Procedure sections have been updated to include the latest prognostics bulletin verbiage. The Warranty section has also been updated to include Peterbilt specific SRT codes for filing cross-division repairs.
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."
E3382026-05-06. Service campaign. ENGINE. Certain EPA21 PACCAR MX engines are equipped with PHINIA fuel injectors that do not meet PHINIA’s manufacturing specifications.
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.
01-0902025-12-05. Service bulletin. ENGINE. Repair procedures and warranty information for model 520EV are now available. The cab heater coolant system on Peterbilt 579EV and 520EV models may not deaerate properly, causing pump malfunctions and inadequate cab heating. Update coolant deaeration return line parts and procedures are now available to release trapped air back to the reservoir.
R24052025-11-05. Service bulletin. ENGINE; ELECTRICAL SYSTEM. All parts necessary to complete Phase 2 of this bulletin are now available. This retrofit provides certain chassis equipped with Cummins X15N (Natural Gas) engines with production level parts to replace preproduction parts installed at the time of manufacture.
CE0332025-08-05. Warranty extension. ENGINE. 32 fuel injector part numbers (16 for MX-11 and 16 for MX-13) have been added to this warranty policy.
R2306 - PB2025-07-02. Service bulletin. ENGINE. All EMUX retrofit procedures updated to make it clear that the VECU3 must have software updated and vehicle mileage confirmed correct before updating the Digital Display. Parts and Procedure section also updated to include the Vehicle Emissions Control Information label ordering and installation instructions. This label is required for all chassis involved in R2306. Included additional reference to Cummins bulletin C7014 in the procedure section for ordering emissions labels.
E3182025-07-02. Service bulletin. ENGINE; FUEL/PROPULSION SYSTEM. Newly designed fuel injectors are available for EPA2021 compliant PACCAR MX-series engines to optimize engine performance. Injectors must be replaced as a full set (6 injectors) and associated software must be updated at the same time.
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.
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.

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