Vehicle report

2025 PETERBILT 520

Service bulletins

39 bulletins

Technical service bulletins are instructions a manufacturer sent its dealers about a known fault. They are not recalls and the work is usually not free, but they are the clearest signal of a problem the manufacturer already knows about.

P001

Service Bulletin/Repair Instructions

KW: The chassis list has been updated to include 1 chassis. The total chassis count is now 53. A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section. PB: The chassis list has been updated to include 8 chassis. The total chassis count is now 130. A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section.

P002

Service Bulletin/Repair Instructions

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.

43-089

Service Bulletin/Repair Instructions

This optional software update is expected to be available after 08/28/2026.

24KWC/24PBC

Service Bulletin/Repair Instructions

Updated Sheppard Steering Gear Classification Tool link in Inspection Procedure

24KWL/PBL

Service Bulletin/Repair Instructions

The verbiage in the Introduction section has been updated.

43-088

Service Bulletin/Repair Instructions

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.

46-029

Service Bulletin/Repair Instructions

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.

46-020

Service Bulletin/Repair Instructions

Certain unaffected chassis have been removed from the chassis population.

E318

Service Bulletin/Repair Instructions

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.

25KWD 25PBD

Service Campaign

Additional US chassis have been added, along with additional Canadian chassis under identical safety recall 26PACB.

26PACB

Service Campaign

(KW): Certain Kenworth K270 and K370 Battery Electric Vehicle (BEV) chassis equipped with certain DANA cradle harnesses may intermittently lose electrical continuity at one or more C40 connector pins. This can occur without warning and cause loss of propulsion, increasing the risk of a crash. Certified BEV technicians will inspect the C40 connector and replace the cradle harness, if necessary. This safety recall defect is identical to 25KWD and applies to certain Canadian chassis added on 07/02/2026. (PB): Certain Peterbilt Model 220 Battery Electric Vehicle (BEV) chassis equipped with certain DANA cradle harnesses may intermittently lose electrical continuity at one or more C40 connector pins. This can occur without warning and cause loss of propulsion, increasing the risk of a crash. Certified BEV technicians will inspect the C40 connector and replace the cradle harness, if necessary. This safety recall defect is identical to 25PBD and applies to certain Canadian chassis added on 07/02/2026.

43-080

Service Bulletin/Repair Instructions

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.

26PACA

Service Bulletin/Repair Instructions

​Updated cross shaft and bearing installation steps have been added to the repair procedures.

99-051

Emissions

There is an update to the CARB Base Emissions Warranty Limits table and Manufacturer’s Warranty Coverage section in certain Engine Model Year (EMY) 2025 MX-11 and MX-13 Operator’s Manuals.

46-028

Service Campaign

Certain Peterbilt Model 520 BEV chassis with an Accelera Power Control and Accessory System (PCAS) were manufactured without a check valve in the power steering system.

E338

Service Campaign

Certain EPA21 PACCAR MX engines are equipped with PHINIA fuel injectors that do not meet PHINIA’s manufacturing specifications.

E326

Emissions

EPA17-24 MX Fuel Injector Connector - This bulletin has been revised to include all EPA17-24 and CARB24 PACCAR MX engines.

15-034

Service Campaign

Battery Electric Vehicle (BEV) de-energizing and re-energizing procedures have been added to the bulletin for Peterbilt Model 520 BEV.

46-024

Service Bulletin/Repair Instructions

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.

25PACF

Service Bulletin/Repair Instructions

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.

01-090

Service Bulletin/Repair Instructions

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.

46-019

Service Bulletin/Repair Instructions

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.

R2405

Service Bulletin/Repair Instructions

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.

CE033

Warranty Program/Extension

32 fuel injector part numbers (16 for MX-11 and 16 for MX-13) have been added to this warranty policy.

E323

Service Bulletin/Repair Instructions

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 - PB

Service Bulletin/Repair Instructions

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.

98-030

Service Bulletin/Repair Instructions

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.

25PBC

Service Bulletin/Repair Instructions

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.

46-016

Service Campaign

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.

R2405 - PB

Service Bulletin/Repair Instructions

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

43-080 PB

Service Campaign

As of 03/25/2025, this campaign has resumed. Software updates are now available to complete this campaign.

E327

Emissions

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. 11014768 20250304 E327 20250227 E327 Emissions PETERBILT 389 2025 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.

24PBK

Service Bulletin/Repair Instructions

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.

24PBL

Service Bulletin/Repair Instructions

Safety Recall Updated software and procedures are now available. Certain Vehicle Model Year 2021-2025 Peterbilt chassis configured for trailer towing require a software update for the Bendix EC80 ABS ECU. Software update procedures for certain Battery-Electric Vehicles (BEV) and EC80 ABS ECU part numbers are not yet available. This bulletin will be updated when software update procedures are available for these chassis. Safety Recall publish date: 1/10/25

46-011

Service Bulletin/Repair Instructions

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.

E290

Service Bulletin/Repair Instructions

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.

46-001 HVAC Update

Other

BEV Phase 2 tools have been added to the BEV required tools lists.

E307

Service Bulletin/Repair Instructions

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.

15-031

Service Bulletin/Repair Instructions

This Bulletin contains parts ordering and replacement procedures for Steering Gears identified as SUSPECT under 24PBC ONLY. Steering Gears repaired under this bulletin MUST be entered into the Serial Number Tracking Form for 24PBC.

Reading this report

Complaint counts are reports filed with NHTSA, not failure rates. A common model collects more of them than a rare one that breaks more often.

2025 Peterbilt 520 Service Bulletins: 39 bulletins | CarFathom