TSB - DATA COLLECTION: EXTRACT CALIFORNIA EMISSIONS DATA FROM ECU (DC21) - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information related to extracting “in use performance tracking†emissions data from the Engine Control Unit (ECU) of certain vehicles sold in California. The California Air Resources Board (CARB) requires the emissions data from vehicles with a minimum of 3,000 accumulated miles without reprogramming or resetting.