Bulletin 54-088 -

Changes may be required to match production updates for the expansion modules ( XMC1 and XMC2 Wiring Configurations:

: Manufacturers like Daimler Trucks North America often view these bulletins as necessary maintenance. Failure to perform required campaign work in a reasonable timeframe can sometimes result in the denial of future related warranty claims. ICU2M to ICU4M Conversion - nhtsa bulletin 54-088

This bulletin is not a simple "plug-and-play" instruction manual. It involves complex technical steps, including: Changes may be required to match production updates

It is possible you are thinking of one of the following, or perhaps this is a prompt for a new story: bulletin 54-088

: Daimler Trucks North America (DTNA) often mandates following these bulletins to ensure the vehicle meets safety and environmental standards. Related Technical Documentation