2020 Kenworth C500 TSBs

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.

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.

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."

This is not a stand-alone procedure. Cummins Quickserve troubleshooting will specify the use of these procedures while troubleshooting specific fault codes.

requirements per FMVSS/CMVSS 121 Air Brake Systems. This bulletin will be updated when repair parts and procedures are available.

On certain Kenworth model years 2018 through 2024 C500/T660/T800/W900 trucks with Sears Atlas 70 or 80 series seats, a spacer was installed on the seatbelt mounting assembly. In a severe collision, the ICP bar may fail, increasing the risk of injury.