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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: Electrical system are shown. Show all

Bulletins, newest first
P0012026-08-20. Service bulletin. ELECTRICAL SYSTEM; ENGINE. Chassis list has been updated to include 10 chassis. The total chassis count is now 101.
46-0292026-08-20. Service bulletin. ELECTRICAL SYSTEM. When DAVIE version 26.21.2 is used to update the VECU3 to software version 3.4.46.0, the VECU3 5071 component group may display as --- after programming.
46-0202026-07-23. Service bulletin. UNKNOWN OR OTHER; ELECTRICAL SYSTEM. Certain unaffected chassis have been removed from the chassis population.
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.
25KWD 25PBD2026-07-20. Service campaign. ELECTRICAL SYSTEM; FUEL/PROPULSION SYSTEM. Additional US chassis have been added, along with additional Canadian chassis under identical safety recall 26PACB.
43-0802026-06-17. Service bulletin. ELECTRICAL SYSTEM. "KW: A new recommended repair has been added to verify the software level and close the campaign in SIR.The repair procedure has been updated with additional note boxes for clear instructions. PB: The repair procedure has been updated with additional note boxes for clear instructions."
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.
46-0242026-01-06. Service bulletin. ELECTRICAL SYSTEM. Certain Battery Electric Vehicles that are subject to California Air Resources Board (CARB) regulations have Vehicle Emissions Control Information (VECI) labels that are missing the CARB Enhanced EV and FCEV Statement.
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.
98-0302025-06-05. Service bulletin. ELECTRICAL SYSTEM. 5/29/2025: A new Ethernet Multiplexed Architecture (EMUX) Service Tool Kit service manual (SM034-022) has been released to provide general use information. The new EMUX Service Tool Kit improves cab & chassis electrical troubleshooting efficiency, while reducing risk of component damage. 4/29/2025: The Ethernet Multiplexed Architecture (EMUX) Service Tool Kit and individual kit components are now available to order. Dealers that have received their first kit may order an additional kit. The EMUX Service Tool Kit Part number has been updated to match OEM drawings (P74-1045-001). Individual kit component part numbers can be found in the Reference Bill of Materials sheet. The new EMUX Service Tool Kit improves cab & chassis electrical troubleshooting efficiency, while reducing risk of component damage. Information Only New diagnostic tool is required to support PACCAR Ethernet Multiplexed Architecture (EMUX). The EMUX Service Tool Kit will help improve cab & chassis electrical troubleshooting efficiency, while reducing the risk of component damage.
25PBC2025-05-06. Service bulletin. ELECTRICAL SYSTEM. Safety Recall – Interim Notification Certain Battery Electric Vehicle (BEV) chassis equipped with certain Accelera High Voltage Interlock Loop (HVIL)circuit configurations may experience a sudden loss of high voltage power with unintended opening of electrical contactors, which may occur without warning. This can result in a loss of propulsion and may increase the risk of a crash. This bulletin will be updated once parts and procedures are available.
46-0162025-05-06. Service campaign. ELECTRICAL SYSTEM. 4/29/2025: Campaign A software update is available for 520EV and 579EV Battery Electric Vehicles. This software update corrects or improves certain functions. Software update procedures have been revised. Campaign start date is 12/05/2024. Campaign A software update is available for 520EV and 579EV Battery Electric Vehicles. This software update corrects or improves certain functions. Campaign start date is 12/05/2024.
25PBC2025-05-06. Service bulletin. ELECTRICAL SYSTEM. Certain Peterbilt Battery Electric Vehicle (BEV) chassis equipped with certain Accelera High Voltage Interlock Loop(HVIL) circuit configurations may experience a sudden loss of high voltage power with unintended opening of electrical contractors, which may occur without warning. This can result in a loss of propulsion and may increase the risk of a crash. Software version verification, along with the installation of an upgraded circuit overlay harness kit, is required to address this issue.
43-080 PB2025-04-04. Service campaign. ELECTRICAL SYSTEM. As of 03/25/2025, this campaign has resumed. Software updates are now available to complete this campaign.
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.
R2306 - PB2024-12-03. Service bulletin. ELECTRICAL SYSTEM. TCS case requirements for EMUX software and PACCAR MX Pack 2 injector upfit have been removed. Software has been campaigned for both processes, and software assistance is no longer required. All EMUX jumper harness retrofit procedures have been updated to include a soft reverification step and procedures for 520, 567 car carrier, and 2.1m MD have been updated to include R&R procedures for VECU3. Parts Matrix has been updated – VECU3 has been added to numerous chassis.
46-0112024-12-02. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN. Some 579EV and 520EV BEV trucks may have loose or improperly torqued ESS gland nuts. This may cause an intermittent warning light on the dash display.
98-0302024-10-05. Service campaign. ELECTRICAL SYSTEM. Information Only New diagnostic tool is required to support PACCAR Ethernet Multiplexed Architecture (EMUX). The EMUX Service Tool Kit will help improve cab & chassis electrical troubleshooting efficiency, while reducing the risk of component damage.
46-001 HVAC Update2024-09-10. Other. ELECTRICAL SYSTEM. BEV Phase 2 tools have been added to the BEV required tools lists.

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