### Question
What is the definition of onboard emissions diagnostic device?


### Answer
The definition of **onboard emissions diagnostic device** is as follows in *42 U.S.C. § 7541*:

> any device installed for the purpose of storing or processing emissions related diagnostic information, but not including any parts or other systems which it monitors except specified major emissions control components

#### Citation:
  - *42 U.S.C. § 7541*
  - Heading: **CHAPTER 85-AIR POLLUTION PREVENTION AND CONTROL > SUBCHAPTER II-EMISSION STANDARDS FOR MOVING SOURCES > Part A-Motor Vehicle Emission and Fuel Standards**

