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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

Bulletins, newest first
46-0242026-02-05. Service bulletin. UNKNOWN OR OTHER. CARB Label Procedure Update The repair procedure removes the aftermarket change request, adds GHG label inspection, and directs dealers to open a TCS365 case to order new labels. Warranty codes for inspection and label replacement have been updated. Certain Battery Electric Vehicles that are subject to California Air Resources Board (CARB) regulations have GHG labels that are missing the CARB Enhanced EV and FCEV Statement.
25PACF2026-01-06. Service bulletin. EXTERIOR LIGHTING. Parts and procedures are now available for all affected chassis equipped with Vehicle Electronic Control Unit (VECU) part number Q21-1157-013-011 / Q21-1157-013-013 / Q21-1157-002-002 / Q21-1157-004-004 / Q21-1157-006-006 / Q21-1157-009-009. See attached Parts Matrix for required parts per chassis.
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.
15-0342026-01-06. Service bulletin. STEERING. Certain Kenworth L770 and Peterbilt Model 520 chassis may encounter a slight increase in effort in the right-hand steering shaft when turning the wheel.
46-0192025-12-05. Service bulletin. UNKNOWN OR OTHER. Repair procedures and warranty information for model 520EV are now available. Certain Peterbilt 579EV and 520EV chassis have the First Responder Guide (FRG) label incorrectly showing the cut loop on the wrong side and are missing the Low Voltage Battery Disconnect Switch and Do Not Jump Start labels. These labels are now available for installation.
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.
25PACF2025-09-03. Service campaign. EXTERIOR LIGHTING. Procedures are now available for Phase 1 chassis equipped with Internal Combustion Engines (ICE) and Vehicle Electronic Control Unit (VECU) part number Q21-1157-013-011 / Q21-1157-013-013. Parts and procedures for Phase 2 chassis will be available at a later date. This bulletin will be updated at that time. Please refer to the condition section for more details. Certain Ethernet Multiplexed Architecture (EMUX) chassis fail to conform to Federal and Canada Motor Vehicle Safety Standards (FMVSS/CMVSS) No. 108. Delayed or unsteady illumination of the vehicle’s stop lamps, reverse lamps, turn signal lamps and inadvertent change in headlamp illumination or lift axle position may"
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.
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.
24PBK2025-02-05. Service bulletin. STEERING. Safety Recall Specific 2024 Peterbilt Model 367, 389, 548, and 2024-2025 520 and 567 chassis equipped with a PACCAR 20k Steer Axle have been identified as having steering arm and/or tie rod arm fasteners that may be improperly torqued and can be at risk of failing. If both fasteners in either steering arm or tie rod arm fail, there may be a loss of steering control, which could increase the risk of a crash. Affected chassis will have all steering arm and tie rod arm bolts removed, replaced with new bolts, and torqued properly.
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.
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.
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.
E2902024-10-05. Service bulletin. FUEL/PROPULSION SYSTEM. FIX-AS-FAIL Updated to include EPA2024 compliant engines. Fuel Filters must be changed before first cleaning. EPA2021 injector cleaning is referenced in RMI for certain injector faults. Complete the procedures in E290. Discard any previous versions of E290 procedures – always use the most current document from the link in the bulletin.
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.
46-0142024-10-05. Service bulletin. UNKNOWN OR OTHER. Information Only Storage guideline procedures are now available for both Medium Duty and Heavy-Duty Battery Electric Vehicles.
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.