USA - Heavy Duty Engine On-Board Diagnostic System Requirements

Through the publication of this notice, CARB is establishing that the effective date for section 2196.2 of the HD I/M regulation is April 1, 2024. This announcement establishes that vehicles subject to the HD I/M regulation must pass an emissions compliance test twice per year, except motorhomes and agricultural vehicles, which must pass an emissions compliance test once per year. The first periodic testing submission deadlines will occur in July of 2024. Following the initial three years of periodic testing requirements, the compliance testing frequency increases to four times per year on April 1, 2027, for vehicles equipped with onboard diagnostics systems.

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