means a system on-board a vehicle or engine which has the capability: (a) of detecting malfunctions, affecting the emission performance of the engine system; and (b) of indicating their occurrence by means of an alert system; and (c) of identifying the likely area of the malfunction by means of information stored in computer memory and communicating that information off-board, seade, mis registreerib mootori põlemisprotsessi tööparameetreid, salvestab need ja kõrvalekaldumiste korral võtab vastu otsuseid, korrigeerides võimaluse korral mootori tööd vajalikus suunas.