1. Reasons for Amendment

 ○ The Amendment aims to improve smoke and exhaust emissions testing standards and methods, etc. to increase the effectiveness of the exhaust emissions testing system for in-use diesel vehicles.

 * Incorporate Board of Audit and Inspection audit findings (Nov 2019 - Mar 2020) concerning permissible emission levels for in-use motor vehicles

 ○ The Amendment prescribes grounds on which to test for the normal operation of selective catalytic reduction (SCR)* systems in relation to nitrogen oxide exhaust emissions, and otherwise addresses weaknesses in the operation of the testing system.

 * SCR (Selective Catalytic Reduction): A system to reduce nitrogen oxides by converting them into oxygen (O2) and nitrogen (N2) through a catalytic reaction of diesel exhaust fluid (DEF) and NOX 

2. Major Provisions

A. Improve smoke and exhaust emissions testing standards and methods for diesel motor vehicles

 1) Delete the provision stating “permissible emission levels relaxed by 5%” applied to smoke tests (snap acceleration) for some vehicles equipped with a supercharger* from 1993 (attached Table 21, subparagraph 1, item J)

 * Relaxed by 5% as larger volumes of smoke may be produced due to temporary airflow disruption → Rendered unnecessary by current performance improvements

 2) Apply DPF performance retention testing standards for diesel vehicles (smoke not more than 10%) and expand from small/medium to also include large diesel vehicles (attached Table 21, subparagraph 2, item B; subparagraph 3, item B, remark 2)

 3) Ensure the effectiveness and consistency of regular inspections by clarifying the no-load testing method (attached Table 22, subparagraph 1, item D, remark 1)

 - Prevent confusion with the testing method by specifying in detail: Reach maximum RPM within 4 seconds and snap accelerate within 1 second → Once maximum RPM is reached, maintain for 1 second → Keep idling for 5 to 10 seconds

B. Expand nitrogen oxide testing system for in-use diesel vehicles

 1) Prevent arbitrary manipulation of selective catalytic reduction (SCR) systems by expanding the test from small/medium to also include large trucks (attached Table 21, subparagraph 3, item B, remark 2)

 2) Expand applicability from only the Seoul metropolitan area to air control zones starting from 2025 (attached Table 21, subparagraph 3, item B, remark 3)

 3) Prescribe grounds on which to test for the normal operation of sensors associated with selective catalytic reduction systems under exhaust emissions test items (operation status check of parts/systems) (attached Table 26, subparagraph 2, item B) 

C. Update provisions to align with other laws, etc.

 1) Specify that any diesel vehicle that is registered in a sophisticated inspection zone shall be subject to permissible emission limits for sophisticated inspection zones when undergoing any reconfiguration or temporary inspection* (attached Table 21, subparagraph 3, item B, remark 4)

 *Motor Vehicle Management Act, Enforcement Decree of the Passenger Transport Service Act

 2) Specify the requirement that the facility of any maintenance business entity for motorcycles must be a building that has been licensed as a motor vehicle-related facility (attached Table 24, subparagraph 1, item C)

 3) Change the valid period* of sophisticated inspections of motor vehicles to “31 days before and after the expiration date” (attached Table 25, remarks 8 and 9)

 *Rules on Enforcement, etc. of Comprehensive Motor Vehicle Inspections (Ministry of Environment/Ministry of Land, Infrastructure and Transport Joint Directive) amended (March 31, 2019)

 4) Align carbon monoxide test record notation with permissible emission levels for in-use motor vehicles (attached Table 21 of Enforcement Rule) (attached Table 26, subparagraph 3, item B, (3) (B))

C. Simplify document submission through administrative data matching

 1) Omit submission of regular motorcycle inspection application documents that can be viewed electronically (Article 86-2, paragraph 1)

 2) Use administrative data matching for the “motorcycle use declaration certificate” required for regular motorcycle inspection postponement application forms (Article 86-5, paragraph 3; Form 40)