WenmarOpen by Wenmar Pro

Service bulletins for the 2020 Kenworth T680

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.

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

By type

By component

By topic

Only bulletins with component: Engine are shown. Show all

Bulletins, newest first
E2962022-08-30. Service bulletin. ENGINE AND ENGINE 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.
R21032022-02-04. Service bulletin. ENGINE AND ENGINE 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.
42-0592021-12-02. Service bulletin. ENGINE AND ENGINE COOLING:COOLING SYSTEM:FAN; ENGINE AND ENGINE COOLING. Non-Safety Campaign â“ 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.
21KWD2021-07-06. Service bulletin. ENGINE AND ENGINE 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 .
32-0182021-03-10. Service bulletin. ENGINE AND ENGINE COOLING. Non-Safety Campaign – Chassis with the City Horn option may generate unexpected alerts. A VECU software update is available to resolve the issue.
E2752021-01-06. Service bulletin. ENGINE; EQUIPMENT:OTHER:LABELS; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL. 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
37-0012020-09-03. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING. Fix-As-Fail – The Master Switch Module (MSM) may lose dash switch memory and functionality when the battery disconnect switch is cycled. An improved MSM is available to resolve the issue.
01-0752019-12-04. Service bulletin. ENGINE AND ENGINE COOLING. Information Only: This bulletin provides guidance for repairing an air-conditioning system after internal failure of the A/C compressor.
TIB43-0622019-10-04. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. Information Only – This bulletin provides information about the California Air Resources Board (CARB) Periodic Smoke Inspection Program (PSIP) and Heavy Duty Vehicle Inspection Program (HDVIP).
42-0582019-09-05. Service bulletin. ENGINE AND ENGINE COOLING. Fix-As-Fail: Two separate causes have been identified as root cause of intermittent low coolant indicator illumination.

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