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Service bulletins for the 2026 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.

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

By type

By component

Only bulletins with type: Service bulletin are shown. Show all

Bulletins, newest first
42-0702026-10-17. Service bulletin. UNKNOWN OR OTHER. Due to supplier constraints, an authorized aftermarket surge tank has been made available.
P0012026-09-29. Service bulletin. ENGINE. "Kenworth: Dealers should check the chassis list and SIR weekly for VIN changes. 2 chassis added to the chassis list. Peterbilt: Dealers should check the chassis list and SIR weekly for VIN changes. 10 chassis added to the chassis list."
P0012026-09-23. Service bulletin. ENGINE. "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."
P0012026-08-27. Service bulletin. ENGINE. "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."
43-0892026-08-25. Service bulletin. ENGINE. This optional software update is expected to be available after 08/28/2026.
P0012026-08-25. Service bulletin. ENGINE. "PB: The chassis list has been updated to include 11 chassis. The total chassis count is now 122. KW: The chassis list has been updated to include 3 chassis. The total chassis count is now 52."
P0012026-08-20. Service bulletin. ENGINE. "KW -The chassis list has been updated to include 2 chassis. Total chassis count is now 49. PB - The chassis list has been updated to include10 chassis. The total chassis count is now 111."
24KWC/24PBC2026-08-20. Service bulletin. STEERING. Updated Sheppard Steering Gear Classification Tool link in Inspection Procedure
43-0892026-08-20. Service bulletin. ENGINE. This optional software update is expected to be available in late August 2026 for chassis equipped with EPA 2024 EMY 2024-2026 PACCAR MX-11 and MX-13 engines. This bulletin will be updated when the software is ready. 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. The procedure document has also been updated for clarity.
43-0892026-08-20. Service bulletin. ENGINE. This optional software update is expected to be available in late August 2026 for chassis equipped with EPA 2024 EMY 2024-2026 PACCAR MX-11 and MX-13 engines. This bulletin will be updated when the software is ready. 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. The procedure document has also been updated for clarity.
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.
43-0892026-08-01. Service bulletin. ENGINE. This optional software update is expected to be available on 08/07/26 for chassis equipped with EPA 2024 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.
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.
99-0522026-07-20. Service bulletin. UNKNOWN OR OTHER. There is an update to the Base Emissions Warranty Limits table [PR1.1]and general certification information in certain Engine Model Year (EMY) 2026 MX-11 and MX-13 Operator’s Manuals.
26PACA2026-06-03. Service bulletin. STEERING. Updated cross shaft and bearing installation steps have been added to the repair procedures.
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.

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