The validation test shall be conducted on a chassis dynamometer, as far as applicable, under type-approval conditions by following the requirements of Annex 4a to UN/ECE Regulation No 83, 07 series of amendments or any other adequate measurement method. It is recommended to conduct the validation test with the worldwide harmonised light vehicles test cycle (WLTC) as specified in Annex 1 to UNECE Global Technical Regulation No 15. The ambient temperature shall be within the range specified in point 5.2 of this Annex.

It is recommended to feed the exhaust flow extracted by the PEMS during the validation test back to the CVS. If this is not feasible, the CVS results shall be corrected for the extracted exhaust mass. If the exhaust mass flow rate is validated with an exhaust mass flow meter, it is recommended to cross-check the mass flow rate measurements with data obtained from a sensor or the ECU.