WenmarOpen by Wenmar Pro

Service bulletins for the 2023 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.

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

By type

By component

By topic

Bulletins, newest first
14-0342026-05-06. Service bulletin. UNKNOWN OR OTHER. Bogie Crossmember Torque Value Update - Procedure has been updated to correct torque values.
E3352026-05-06. Emissions. ENGINE. E335 Warranty wording update Apr 2026
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.
01-0902026-04-07. Service bulletin. UNKNOWN OR OTHER. Bulletin Update 03/02/2026 - A Meritor OnTrac case submission is required prior to repairs being completed. Failure to do so may result in warranty claim denial. See the procedure section for more details.
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.
14-0362026-04-07. Other. STRUCTURE:BODY. One-Piece Aluminum Crossmember Repair - Repair procedures are available to support the replacement of intermediate or midship one-piece aluminum crossmembers.
22KWE/PBE2026-04-07. Service bulletin. STEERING. Sheppard Recall Order Process Update - The Parts section has been updated with revised steps for opening a TCS365 Order Support – Order Inquiry case.
24PBE_KWE2026-03-05. Service bulletin. ELECTRICAL SYSTEM. The Parts section has been updated to clarify that freight charges for safety recall orders should not be passed on to the end customer.
CE0312026-03-05. Warranty extension. ENGINE. Fuel Injection Pump part number 2344776PEX for MX-13 engines has been added to this warranty policy.
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.
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.
FS0152025-12-05. Service bulletin. POWER TRAIN. Certain chassis equipped with a PACCAR TX-12 transmission have Mechatronic Transmission Module (MTM) rail cylinder cap screws that could become loose. This may cause the transmission not to shift and the transmission service lamp to illuminate.
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.
24PBE2025-12-05. Service campaign. ELECTRICAL SYSTEM; POWER TRAIN. The right-hand shift stalk may have an improper wire harness terminal crimp within the wire harness connector. Loss of communication between the right-hand shift stalk and the vehicle may result in the vehicle being disabled after it comes to a stop, thereby increasing the risk of crash or injury. A warning will appear on the dash display when communication is lost, including transmission or engine warnings, “!” next to DNR/DNRP indicator, “-“ in the DNR/DNRP indicator, and/or chimes, depending upon whether you are operating a diesel/gas or battery electric vehicle.
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.
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.
T016 / 26-0402025-06-05. Service bulletin. POWER TRAIN. T016: Warranty section updated to include 0.5 hours for test drive. Recommended Repair T016C has been updated from 6.4 hours to 6.9 hours. SRT codes updated in PRWS Claim Coding Table: B25-17A for 6.9 hours created to replace all other codes. 26-040: Warranty section updated to include 0.5 hours for test drive. Recommended Repair 26040C has been updated from 6.4 hours to 6.9 hours. SRT codes updated in PRWS Claim Coding Table: B25-17A for 6.9 hours created to replace all other codes.
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.
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.

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