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Service bulletin C2690

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.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id10249561
Published by NHTSA2024-02-02
Manufacturer's numberC2690
Manufacturer's date2024-01-30
NHTSA componentENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM):SOFTWARE; ENGINE AND ENGINE COOLING; ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM)

NHTSA's summary

This emission campaign is being issued to recalibrate the Engine Control Module (ECM) on certain 2021 B6.7 Hybrid bus engines. The campaign enables authorized repair locations to calibrate the engine control module (ECM) to the latest revision. This calibration update may provide improvements to the monitoring frequency of certain on-board diagnostics in order to meet the in-use monitor performance ratio (IUMPR) requirements.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Engine, Engine control module

Vehicles listed
CUMMINS B6.7

Listing a model year does not mean every vehicle of it is concerned: the document says which.