2020 Kenworth T680 Technical Service Bulletins

67 technical service bulletins (TSBs) are on record for the 2020 Kenworth T680. 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.

• 11037549Sep 23, 2026Electrical system. This bulletin, the troubleshooting procedure, and the BMS Troubleshooting Checklist have been updated to show that the Autometer tool test results can be used in place of the Midtronics tool test results for fulfilling service and warranty requirements.
• 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.
• 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."
• 11035107Jul 3, 2026Transmission and drivetrain. Updated Eaton's TAIB0885EN Bulletin link.
• 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."
• 11033916Jun 6, 2026Engine. The PACCAR Powertrain Prognostics Webcast video link has been removed. It will be included with updated information at a later date.
• 11033373May 18, 2026Engine. Kenworth - The Warranty section has been updated to include Peterbilt-specific SRT codes for cross-division repair filing.
• 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, 2026Electrical system, Engine. 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.
• 11030922Mar 6, 2026Engine. EPA17-24 MX-13 Fuel Injector Connector - This bulletin has been revised to include EPA24 PACCAR MX-13 engines.
• 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.
• 11027058Dec 31, 2025Fuel system. Certain vehicle model years 2020-2025 K270, K370, T270, T280, T370, T380, T480, T680, T880, W900 chassis have updated Greenhouse Gas (GHG) labels available for installation.
• 11024956Oct 28, 2025Brakes. SAFETY RECALL Additional chassis have been included. The chassis list has been updated. Certain T370 / T440 / T470 / T480 / T660 / T680 / T800 / T880 / W900 / C500 chassis may be equipped with air tank reservoirs that have less than twelve times the combined volume of all service brake chambers which fail to conform to Federal Motor Vehicle Safety Standard (FMVSS) No.121, Air Brake Systems.
• 11022496Aug 20, 2025Engine, Transmission and drivetrain. 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.
• 11000765May 21, 2024Engine. Campaign Certain PACCAR MX-13 engines contain bolts for the main bearing caps which may fail under certain conditions.
• 10254164Apr 9, 2024Brakes. Certain C500/T440/T470/T660/T680/T800/T880/W900 chassis may have air tank reservoirs that do not meet air volume requirements per FMVSS/CMVSS 121 “Air Brake Systems”. This bulletin will be updated when repair parts and procedures are available.
• 10243362Sep 1, 2023Body and structure. Replacement fuel bezels are available for T680 Next Gen fairings. New bezels have updated attachments to prevent the bezel from becoming loose.
• 10243358Sep 1, 2023Engine cooling, Transmission and drivetrain. Certain T680 Next Gen Cummins X15 have fan hub bracket hardware that is under torqued and could become loose and/or fail. Procedures are available to replace and properly torque the hardware.
• 10238382Jun 2, 2023Engine cooling. Certain chassis with Engine Model Year 2016-2021 PACCAR MX-11/MX-13, or EPA13 and EPA21 Cummins ISX12/ISX15/X15 engines that had a previously failed DEF sensor and with DEF sensor software disabled due to industry DEF sensor shortages will now be able to receive a replacement DEF sensor, DEF tank heater coolant control valve, and re-enabled DEF diagnostic software.
• 10232496Feb 24, 2023Engine cooling, Fuel system. Certain Model Year 2021-2024 chassis with PACCAR MX engines and optional fuel filter restriction virtual gauge may display incorrect restriction levels. The virtual gauge will be temporarily disabled until a revised sensor strategy is developed.
• 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.
• 10225581Oct 18, 2022Engine cooling. Certain T680 NextGen air filter elements that may have been damaged due to excessive vibration were replaced without inspecting the air intake system for dust intrusion. Those vehicles must be inspected to assess possible progressive damage."
• 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.
• 10218895Aug 3, 2022Engine cooling. Kenworth is providing guidance for PACCAR MX Engine Composite Oil Pan leak troubleshooting to avoid over-repairs and to provide warrantable repair guidance. Oil leaks, if not repaired, can lead to severe engine damage.
• 10213089May 10, 2022Steering. Safety Recall – Interim Notification - The Dana D-Series front axle steer arm fasteners that attach the steer arm to the steering knuckle may fail, increasing the risk of a crash or injury. Repair information will be added when a repair procedure and parts are available.
• 10208770Feb 4, 2022Electrical system, 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
• 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.
• 10206097Dec 2, 2021Transmission and drivetrain. Non-Safety Campaign: ​Drivers of vehicles equipped with PACCAR TX-12 transmissions may experience harsh shifts and gear grinding noise. Premature Main Drive Gear damage may occur due to clutch housing and main case countershaft bearing bore wear.
• 10206084Dec 2, 2021Transmission and drivetrain. Non-Safety Campaign:Â Eaton Endurant transmissions may experience premature Main Drive Gear damage due to clutch housing and main case countershaft bearing bore wear. A Clutch Housing Front Cover Kit will be installed to address the issue.
• 10203772Nov 15, 2021Engine cooling. Non-Safety Campaign – Vehicles with a Cummins X15 engine and Horton fan drive may set Diagnostic Trouble Code (DTC) 6637 and/or 3838 due to fan speed that results in the fan remaining activated until the power is cycled. A new controller will resolve the issue.
• 10201965Sep 21, 2021Fuel system. 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.
• 10201956Sep 20, 2021Body and structure. Information Only - Rear axle Quarter Fenders with less than two inches of clearance between the top of the quarter fender and the bottom of the trailer/equipment are susceptible to damage. The lack of clearance could result in cracked/broken quarter fenders or complete separation if undetected or un-remedied. ​
• 10198762Jun 14, 2021Engine cooling. Information Only – C hassis equipped with MY2021 B EPA emission s standards will be shipped through atleast the end of the 2021 calendar year without particulate matter (PM) sensors installed .
• 10188468Feb 25, 2021Engine cooling. Non-Safety Campaign – Chassis with the City Horn option may generate unexpected alerts. A VECU software update is available to resolve the issue.
• 10188467Feb 25, 2021Electrical system. Non-Safety Campaign – The batteries may drain quickly due to the VECU not going to sleep. Updated VECU software is available to resolve the issue.
• 10188550Feb 10, 2021Equipment, Visibility (wipers, defrost, mirrors). Information Only – Windshield washer pumps have a high No Trouble Found rate. Washer pumps may fail to spray due to a clogged filter.
• 10185191Dec 22, 2020Engine, Equipment, Engine cooling. Non-Safety Campaign - Vehicles included in Model Year 2021 Pre-Production Engine program have an Emissions Exemption label that must be replaced. The current Emissions Exemption label will expire on 12/31/2020 and requires a new label to extend the exempt
• 10185190Dec 18, 2020Transmission and drivetrain, Equipment, Electrical system. Fix-As-Fail - Prior versions of Eaton Endurant transmission software may be prone to setting Linear Clutch Actuator (LCA) fault codes leading to possible LCA hardware replacement.
• 10182216Oct 12, 2020Electrical system. Fix-As-Fail – The Battery Management System (BMS) may report the incorrect battery condition. Additional diagnostics are available to correctly determine and repair the root cause of the issue.

← All problems reported for the 2020 Kenworth T680