Service bulletins for the 2021 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.
57 on file from NHTSA, as of 2026-10-19.
By type
By component
| 7-700 | 2024-11-05. Warranty extension. POWER TRAIN; ENGINE. 7/700 Service Agreement - Letter Only. |
|---|---|
| E290 | 2024-10-05. 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. |
| 98-030 | 2024-10-05. 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. |
| 46-014 | 2024-10-05. Service bulletin. UNKNOWN OR OTHER. Information Only Storage guideline procedures are now available for both Medium Duty and Heavy-Duty Battery Electric Vehicles. |
| 16-044 | 2024-08-02. Service bulletin. SUSPENSION. Fix As Fail The height control valve (HCV) rod on vehicles with low air leaf suspensions is prone to toggling over center during rough road conditions. With full suspension articulation, HCV bracket flexes and toggles over center the HCV linkage, which results in either deflated airbags or makes them unable to inflate. Fix-as-fail start date is 07/30/2024. |
| E290 | 2023-12-02. Service bulletin. ENGINE AND ENGINE COOLING. Updated procedures and SRT time to include Fuel Filter replacement during cleaning process. Removed in-tank additive references. |
| 46-003 | 2023-11-10. Service bulletin. ELECTRONIC STABILITY CONTROL:AUTOMATIC (ASC). A software fix for model 520EV that are not equipped with ESP (Stability Control) is now available. The currently available soft ware, part number:SCM_1p5_BC_R5p00_003, will address issues caused by software version R5.00_002 that affect Peterbilt Model 520EV. The software update will correct the following issues: 1.) Power gauge displays axle RPM instead of power draw, 2.) Air conditioning compressor is inoperative below 10 mph (16 kmh) and over 40 mph (65 kmh), 3.) Low air and low coolant audible alarms (buzzers) are inoperative below 10 mph (16 kmh), and 4.) (520EV Only) Does not charge without ignition in on position. |
| E306 | 2023-11-10. Service bulletin. FUEL SYSTEM, DIESEL. Incorrect fuel filter drain and replacement procedures on EPA21 MX-11 and MX-13 engines can result in the following: .Debris and contaminants introduced into the high-pressure fuel system. .Denial of warranty claims for injector and/or fuel system faults. .Misfire, rough running, engine knock, and other associated faults and symptoms. Correct fuel filter procedures are outlined in attached service documentation. |
| R2304 | 2023-08-03. Service bulletin. ELECTRICAL SYSTEM. Quality and Volume Validation vehicles built for the 520 VMUX program between July 2019 and December 2020 are eligible for a retrofit of the digital display to a production intent unit that features updated base software, secured hardware, and the ability to be updated with software released after February 2021. |
| E300 | 2023-05-05. Service bulletin. ENGINE AND ENGINE COOLING. PACCAR will reimburse customers for the local purchase of in-tank fuel additive for EPA2021 compliant MX engines. This is a one-time reimbursement. Only customers who have received E290 injector cleaning qualify for this reimbursement. See bulletin for limits and purchase tracking requirements. |
| E290 | 2023-05-05. Service bulletin. ENGINE AND ENGINE COOLING. FIX-AS-FAIL – Updated procedures and claim filing information. EPA2021 injector cleaning is referenced in RMI for certain injector faults. Complete the procedures in E290. Refer to E300 for in-tank additive information. |
| 45-064 | 2022-11-02. Service bulletin. ENGINE AND ENGINE COOLING. Info Only - PACCAR is introducing Over-the-Air (OTA) software updates for engine MY17 and newer chassis equipped with Cummins X15, X12, ISX12, ISX12N, L9N, PX-7, and PX-9 engines The technology will leverage the existing Remote Diagnostic cs hardware to deliver secure software updates remotely. This will reduce downtime and save on maintenance costs for eligible vehicles. |
| 13-060 | 2022-09-06. Service bulletin. SERVICE BRAKES. The service information for Bendix Air Dryer maintenance is being updated to include new procedures. |
| 01-085 | 2022-08-04. Service bulletin. VISIBILITY. Info Only – Certain 520 model chassis built between 2014 and 2021, and equipped with the Red Dot HVAC system, may have service port spacing which will not allow the connection of a pressure gauge to both the high and low side service ports simultaneously. A specific tool is available from the supplier that will allow a technician to bypass this design issue. |
| E294 | 2022-06-02. Service bulletin. FUEL SYSTEM, GASOLINE. Information Only - This bulletin is to provide information about the availability of a fuel filter set for Pre-Production or Validation level chassis. This fuel filter set is available directly from a PACCAR dealership parts department. |
| E290 | 2022-04-06. Service bulletin. ENGINE AND ENGINE COOLING. This bulletin provides information on the EPA21 MX fuel injector cleaning procedure and includes suggested fuel system cleaning fluids. This procedure also provides information to determine if it is necessary to replace the fuel injectors. |
| E286 | 2022-04-05. Service bulletin. FUEL SYSTEM, GASOLINE:FUEL INJECTION SYSTEM:INJECTORS; ENGINE AND ENGINE COOLING; EQUIPMENT. Fix-As-Requested - Engine Model Year 2021B and later PACCAR MX-11 & MX-13 Fuel Injector Adjustment During First C Service |
| TIB 98-020 | 2022-04-05. Service bulletin. EQUIPMENT. Information Only – New Level 1 required tools are available to support MY21B MX engines. |
| 51-013 | 2022-03-04. Service bulletin. EQUIPMENT. Due to major data carriers phasing out 3G networks, chassis currently utilizing first generation Peoplenet Mobile Gateway (PMG001) will experience severe 3G service degradation as early as January of 2022. Chassis currently utilizing 3G antennas as a primary antenna may experience this degradation. |
| E280 | 2022-01-06. Service bulletin. ENGINE AND ENGINE COOLING. Non-Safety Campaign: Certain DC tools were incorrectly calibrated. The resulting torque issue could affect the EPA21 MX-11 and MX-13 Oil Pan and/or the Exhaust Manifold. |
| E282 | 2022-01-06. Service bulletin. ENGINE AND ENGINE COOLING. Information Only: Due to differences between the PACCAR MX-11 or MX-13 2021A and 2021B engines, technicians must be able to identify which of these engines are in a chassis. |
| 43-071 | 2021-10-05. Service bulletin. FUEL SYSTEM, DIESEL. Fix-As-Fail – Due to undersupply issues, only a limited supply of Diesel Exhaust Fluid (DEF) sensors are available. As a temporary solution, after PACCAR confirms a DEF sensor is not available, a temporary software update will allow a vehicle to continue operation with a failed DEF sensor by disabling the DEF sensor diagnostics. |
| 21 PBK | 2021-10-05. Service bulletin. SERVICE BRAKES, AIR. Safety Recall – Certain Model 520 trucks may have been built without a quick release (QR) valve. The absence of this valve could affect rear brake timing on certain vehicles equipped with a tri-drive or liftable tag axle and Dual Seated or Right Hand Stand-Up steering configurations. Vehicles will be inspected and, if necessary, a QR valve will be installed. |
| 21 PBG | 2021-09-04. Service bulletin. FUEL SYSTEM, DIESEL. Safety Recall - Model year 2021 Cummins PX9 fuel hose assemblies may leak from the hoses between the fuel pump and the remote filter head. A fuel leak in the presence of an ignition source may increase the risk of a fire. A repair is now available. |
| 21-PBD | 2021-07-06. Service bulletin. FUEL SYSTEM, GASOLINE. Safety Recall – Cummins Fuel Rail Leak – NHTSA ID: 21V391 / TC: 2021-323, Cummins Recall: C2423. Cummins PX9 and ISX12 fuel rails may leak around a sealing washer, potentially resulting in fuel leaks. Undetected prolonged diesel fuel spray in the presence of an ignition source may increase the risk of fire. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.