An optional software update is expected to be available on or after 07/31/26 for chassis equipped with EPA...

Bulletin number

43-089

Component

Electrical system

Summary

An optional software update is expected to be available on or after 07/31/26 for chassis equipped with EPA 2024 engine model year (EMY) 2024-2026 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.

Owners of these vehicles have filed 1 complaints in the electrical category.