2020 Peterbilt 579 Technical Service Bulletins

104 technical service bulletins (TSBs) are on record for the 2020 Peterbilt 579. TSBs are notes manufacturers send to dealers about repair procedures for issues seen in the field. They are not recalls and do not by themselves mean a vehicle has a fault.

• 11037541Sep 11, 2026Engine. "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."
• 11037451Sep 5, 2026Engine. An exhaust manifold slip joint seal kit is now available for EPA 2017-2024 PACCAR MX-13 engines.
• 11036289Aug 13, 2026Engine. 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.
• 11035343Jul 25, 2026Engine. 105 chassis have been removed from the chassis list and unflagged in PRWS due to expiration of applicable warranty coverage. Total chassis population is 732.
• 11035202Jul 21, 2026Engine. This optional software update is now available for chassis equipped with EMY 2021B-2023 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.
• 11035149Jul 18, 2026Engine. Incorrect air filters may be inadvertently installed in certain chassis equipped with under-hood Donaldson air filter housings.
• 11035111Jul 10, 2026Engine. The Condition, Chassis Affected, Service Action, Warranty, and Procedure sections have been updated to include the latest prognostics bulletin verbiage.
• 11035108Jul 7, 2026Engine. "The software is not yet available. The bulletin will be updated when more information is available."
• 11034394Jun 29, 2026Engine. "An optional software update will be available on 07/06/2026 for chassis equipped with EMY 2021B-2023PACCAR MX-11 and MX-13 engines. This update provides customers with additional time to service theirtrucks before a DEF-related derate occurs. The software is being offered to customers in alignment withrecently updated regulatory agency guidance."
• 11033351May 6, 2026Electrical system. Troubleshooting procedures for 2.1m cab power windows are now available.
• 11032876May 1, 2026Engine. Procedures have been updated to include additional truck models in the service intervals table.
• 11032296Apr 30, 2026Engine. Fix-as-Fail On certain Kenworth T680 chassis equipped with PACCAR MX-13 engines, wiring to the Horton LCX230 crank-mounted fan drive may experience a short due to chafing or water ingress, affecting fan drive operation.
• 11032293Apr 17, 2026Engine. The attached procedures document has been updated with more detail and explanations. This is not a stand-alone procedure. Cummins Quickserve troubleshooting will specify the use of these procedures while troubleshooting specific fault codes.
• 11032292Apr 17, 2026Fuel system. KW & PB DEF Quality Sensor part number Q21-6127-001 for Cummins X15 engines has been added to this warranty policy.
• 11032290Apr 16, 2026Other or unknown. Bogie Crossmember Torque Value Update - Procedure has been updated to correct torque values.
• 11032284Apr 1, 2026Engine, Electrical system. EPA17-24 MX Fuel Injector Connector - This bulletin has been revised to include all EPA17-24 and CARB24 PACCAR MX engines.
• 11030927Mar 11, 2026Engine. 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.
• 11030921Mar 4, 2026Body and structure. One-Piece Aluminum Crossmember Repair - Repair procedures are available to support the replacement of intermediate or midship one-piece aluminum crossmembers.
• 11028314Jan 31, 2026Engine. 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.
• 11022496Aug 20, 2025Transmission and drivetrain, Engine. Condition, Chassis Affected, and Warranty sections updated with the following verbiage “E311 must be flagged and open in Service Information Record (SIR) at the time of RO open date to qualify.” Also, “Through Standard Warranty or any applicable active Extended Warranty” verbiage was removed from Warranty section.
• 11019172May 31, 2025Electrical 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…
• 11019217May 22, 2025Transmission and drivetrain. 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…
• 11017898Apr 30, 2025Electrical 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…
• 11010926Nov 22, 2024Engine. 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…
• 11009757Oct 22, 2024Transmission and drivetrain, Engine. 7/700 Service Agreement - Letter Only.
• 11008566Sep 19, 2024Other or unknown. Information Only Storage guideline procedures are now available for both Medium Duty and Heavy-Duty Battery Electric Vehicles.
• 11008569Sep 14, 2024Electrical 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.
• 11005516Jul 30, 2024Suspension. 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.
• 11000753May 16, 2024Visibility (wipers, defrost, mirrors). Information Only Vehicles equipped with Digital Vision System (DVS) Mirror Mounted Cameras, that do not have optional left-hand or right-hand blind spotters, may set false Diagnostic Trouble Codes (DTC) 522490-9 or 522491-9. These DTCs can be ignored if corresponding blind spotter is not equipped. The next Digital Vision System Mirrors (DVS-M) software update will correct these false DTCs.
• 10245639Nov 2, 2023Engine cooling. Fix As Fail Updated: Two part numbers added: 1818119 DPF Delta Pressure Sensors for MX-13-2 EMY18 2200138 DPF Delta Pressure Sensors for MX-13 -2, EMY19 Per Environment and Climate Change Canada (ECCC) regulations and guidance (Canadian Environmental Protection Act, 1999 (CEPA)), a letter has been provided to owners of Canadian registered chassis that provides a list of emissions components that have been reported…
• 10244481Oct 17, 2023Engine cooling. A testing procedure has been created for the coolant level sensor on model 520.
• 10243354Sep 18, 2023Electrical system. For all Peterbilt chassis equipped with an air shifted PTO. Oil from the air shift cover of the PTO may leak into the air line, causing the EOA solenoid to become inoperative.
• 10243360Sep 1, 2023Engine cooling, Transmission and drivetrain. Certain 579 MLU chassis equipped with Cummins X15 engines have fan hub bracket hardware that are incorrect for the application and/or under torqued and could become loose and/or fail. Procedures are available to replace and properly torque the hardware.
• 10238387Jun 23, 2023Engine cooling, Visibility (wipers, defrost, mirrors). Fix-as-Fail - HVAC Intermittently Stops Blowing Cold Air
• 10237152May 1, 2023Body and structure, Electrical system. Certain 579 chassis are eligible to receive production level Digital Display software, Digital Display, Lane Keep Assist MUX switches, and Kick Panel.
• 10235714Apr 13, 2023Body and structure, Visibility (wipers, defrost, mirrors). Fix As Fail – Certain 579, and New Model 579 chassis that were manufactured with a Bendix forward looking camera system may experience bracket failure causing the bracket and camera to fall from the windshield.
• 10235704Apr 13, 2023Electrical system, Brakes. Fix As Fail – All New Model 579 chassis with Bendix radar opti on may have a harness rub against the radiator that is causing possible damage.
• 10232162Feb 10, 2023Body and structure, Electrical system. Fix As Fail – Chassis that were manufactured with certain battery cable routing brackets may experience rubbing or chafing of the battery cables.
• 10231101Jan 12, 2023Engine cooling. This campaign is the final opportunity to replace the oil filter screw cap to reduce occurrences of broken bypass valve tabs. Broken oil valve tabs can cause oil flow obstruction to critical engine parts, resulting in serious engine damage. Customers that do not receive this repair may be responsible for progressive engine damage caused by broken oil bypass valve tabs.
• 10227172Nov 7, 2022Fuel system, Electrical system. 21PBN – LNG/CNG Methane Detecti on System Will Not Warn Operator if System Loses Power – NHTSA ID:21V00N, TC: 2021-793
• 10225578Oct 18, 2022Engine 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.
• 10222269Sep 9, 2022Suspension. Fix-As-Fail On certain chassis with Low Air Leaf Suspension or Low-Low Air Leaf Suspension, the Height Control Valve (HCV) arm may be rubbing on other components when the bend in the arm is facing outboard. Flipping the bend in the HCV arm inboard prevents the rub.
• 10219233Aug 18, 2022Body and structure. Fix-As-Fail: Forces being applied to the split fender and fairing structure are causing the connection to crack and potentially separate. Reinforcement brackets secure the connection and prevent separation.
• 10219235Aug 3, 2022Brakes. The service information for Bendix Air Dryer maintenance is being updated to include new procedures.
• 10210949Apr 4, 2022Body and structure, Equipment. A roof fairing reinforcement kit increases structural support for one-piece 579 roof fairings that are experiencing fatigue from external forces such as reverse towing.
• 10209699Mar 3, 2022Equipment, Brakes. Fix-As-Fail – A hill start assist (HSA) valve plumbing revision eliminates ice buildup in the HSA valve exhaust in cold weather.Â
• 10208758Feb 4, 2022Equipment. 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.
• 10208756Feb 4, 2022Exterior lighting, Electrical system, Equipment. A frame mounted left-hand marker light bracket interferes with the rear fuel tank fill location. A redesigned bracket can be purchased that relocates the marker bracket to the front fuel tank bracket to eliminate interference.
• 10208714Feb 4, 2022Equipment, Engine cooling. The Turbo Inlet Elbow is susceptible to tearing, potentially allowing dust to enter the engine. The Turbo Inlet Elbow will be replaced with an improved part.
• 10207153Jan 10, 2022Engine cooling. Retrofit - The emissions exemption will be expiring on 5/15/2022 for certain pre-production vehicles equipped with PACCAR MX-11 and MX-13 EPA 2021 Emissions engines. Production-level components are now available to make these vehicles compliant.

← All problems reported for the 2020 Peterbilt 579