WenmarOpen by Wenmar Pro

Service bulletins for the 2025 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.

62 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
E3232025-08-05. Service bulletin. ENGINE. A required spacer tool set is now available to streamline the injector replacement process. The spacer tool set allows certain fuel system components to be loosened instead of removed to provide access to the injectors. See Bulletin 98-031 for details. Tools are not reimbursable through this Bulletin.
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.
R2405 - PB2025-05-06. Service bulletin. ELECTRICAL SYSTEM; ENGINE; FUEL/PROPULSION SYSTEM. Due to parts availability issues, this bulletin will be divided into 2 phases. Phase 1 will enable these chassis to be brought into emissions compliancebefore 06/30/2025 to avoid fi nes and penalties. Phase 2 will include all parts that are not currently available but are necessary to bring chassis up toproduction level. This bulletin will be updated once all Phase 2 parts become available . The emissions exemption for all chassis involved in this retrofi t expires on 06/30/2025. After that date, all chassis that have not received this Retrofi t willbe out of compliance with emissions regulations and illegal to operate . NOTE If emissions exemptions are allowed to expire, vehicle owners could receive civil fines per regulation 40 CFR 19.4 up to $5,911 per engine. In addition, owners may be required to discontinue operation of the vehicle until the retrofit is completed. Campaign start date: 04/18/25
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.
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.

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