   
  
G/TBT/N/USA/1403/Add.5  
 
3 April 2024  
(24-2840) Page: 1/2 
Committee on Technical Barriers to Trade  Original: English  
 
 
NOTIFICATION  
Addendum  
The following communication , dated  2 April 2024, is being circulated at the request of the delegation 
of the United States of America . 
 
_______________  
 
 
Title:  Heavy Duty Engine On -Board Diagnostic System Requirements  
 
Reason for Addendum:  
[ ] Comment period changed - date:   
[ ] Notified measure adopted - date:  
[ ] Notified measure published - date:  
[ ] Notified measure enters into force - date:  
[ ] Text of final measure available from1:  
[ ] Notified measure withdrawn or revoked - date:  
Relevant symbol if measure re -notified:   
[ ] Content or scope of notified measure changed  and text available from1:  
New deadline for comments (if applicable):   
[ ] Interpretive guidance issued and text available from1:  
[X] Other:  
Updated Notice of Effective Dates for Section 2196.2 of the Heavy -Duty Inspection and 
Maintenance Program (HD I/M) - California Code of Regulations Title 13, Chapter 3.7, 
Sections 2195 through 2199.1  
https://ww2.arb.ca.gov/sites/default/f iles/barcu/regact/2024/hd -
im_updated_eff_date_phase3_notice.pdf  
https://members.wto.org/crnattachments/2024/TBT/USA/24_02390_00_e.pdf  
 
Description:  On 29 December 2023, California Air Resou rces Board (CARB) announced an effective 
date of 1 April 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 ta ke effect on 1 October 2024. As of 1 October 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. Follo wing the 
initial three years of periodic testing requirements, the compliance testing frequency increases to 
four times per year on 1 October 2027, for vehicles equipped with onboard diagnostics systems. For 
 
1 This information can be provided by including a website address, a pdf attachment, or other 
information on where the text of the final /modified  measure and/or interpretive guidance can be obtained.  G/TBT/N/USA/1403/Add.5  
 
- 2 - 
 
  further details on these enacted regulatory requ irements, 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 ena cted 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 . 
__________  
 
 