§ 51.357 Test procedures and standards.

Written test procedures and pass/fail standards shall be established and followed for each model year and vehicle type included in the program.

(a) Test procedure requirements. Emission tests and functional tests shall be conducted according to good engineering practices to assure test accuracy.

(1) Initial tests (i.e., those occurring for the first time in a test cycle) shall be performed without repair or adjustment at the inspection facility, prior to the test, except as provided in paragraph (a)(10)(i) of this section.

(2) The vehicle owner or driver shall have access to the test area such that observation of the entire official inspection process on the vehicle is permitted. Such access may be limited but shall in no way prevent full observation.

(3) An official test, once initiated, shall be performed in its entirety regardless of intermediate outcomes except in the case of invalid test condition, unsafe conditions, fast pass/fail algorithms, or, in the case of the on-board diagnostic (OBD) system check, unset readiness codes.

(4) Tests involving measurement shall be performed with program-approved equipment that has been calibrated according to the quality procedures contained in appendix A to this subpart.

(5) Vehicles shall be rejected from testing if the exhaust system is missing or leaking, or if the vehicle is in an unsafe condition for testing. Coincident with mandatory OBD-I/M testing and repair of vehicles so equipped, MY 1996 and newer vehicles shall be rejected from testing if a scan of the OBD system reveals a “not ready” code for any component of the OBD system. At a state's option it may choose alternatively to reject MY 1996–2000 vehicles only if three or more “not ready” codes are present and to reject MY 2001 and later model years only if two or more “not ready” codes are present. This provision does not release manufacturers from the obligations regarding readiness status set forth in 40 CFR 86.094–17(e)(1): “Control of Air Pollution From New Motor Vehicles and New Motor Vehicle Engines: Regulations RequiringOn-Board Diagnostic Systems on 1994 and Later Model Year Light-Duty Vehicles and Light-Duty Trucks.” Once the cause for rejection has been corrected, the vehicle must return for testing to continue the testing process. Failure to return for testing in a timely manner after rejection shall be considered non-compliance with the program, unless the motorist can prove that the vehicle has been sold, scrapped, or is otherwise no longer in operation within the program area.

(6) Vehicles shall be retested after repair for any portion of the inspection that is failed on the previous test to determine if repairs were effective. To the extent that repair to correct a previous failure could lead to failure of another portion of the test, that portion shall also be retested. Evaporative system repairs shall trigger an exhaust emissions retest (in programs which conduct an exhaust emission test as part of the initial inspection).

(7) Steady-state testing. Steady-state tests shall be performed in accordance with the procedures contained in appendix B to this subpart.