USA - Heavy Duty Engine On-Board Diagnostic System Requirements

​​On December 29, 2023, California Air Resources Board (CARB) announced an effective date of April 1, 2024, for section 2196.2 of the HD I/M regulation. Through the publication of this updated notice, CARB is establishing that the effective date for section 2196.2 of the HD I/M regulation will now take effect on October 1, 2024. As of October 1, 2024, vehicles subject to the HD I/M regulation to pass an emissions compliance test twice per year, except motorhomes and agricultural vehicles, which must pass an emissions compliance test once per year. Following the initial three years of periodic testing requirements, the compliance testing frequency increases to four times per year on October 1, 2027, for vehicles equipped with onboard diagnostics systems. For further details on these enacted regulatory requirements, refer to CARB's HD I/M regulation.

Webpage: https://ww2.arb.ca.gov/our-work/programs/CTC

California Code of Regulations, title 13, section 2196.2

For further details on these enacted regulatory requirements, refer to CARB's Clean Truck Check HD I/M regulation webpage at https://ww2.arb.ca.gov/our-work/programs/CTC.

Information regarding CARB's On-Board Diagnostic Program can be found online at https://ww2.arb.ca.gov/our-work/programs/obd. 

Resources about the program are available at https://ww2.arb.ca.gov/resources/documents/obd-resources.​