Malfunction Indicator lamp and Check Engine light ON and How to solved the problem

Malfunction indicator lamp and Check Engine light was ON and this vehical pick-up was lost due to this issue se we connected the Cummins diagnostic tools and scan we found more fault code active and inactive active code was 3577, 3583, 3558 and 2771 inactive code was 3681, 3559 and 4271 we do dozer pump override test then Uria was not injected from injector and Dozer pump pressure was not increasing from 27 so we clean the dosing unit harness and fitted then some active codes gone inactive only one code was active 3583 then we heat the cylensor of SCR system Up to 210dig then this code was also inactive then all the problem got solved