Dosage test with air and reductant under User function in SDP3 can be used as a function check for the entire system after possible faults have been rectified.Check that there is reductant in the tank.Check that the tank ventilation is working.Check if the reductant lines are leaking or are blocked. Pressurise the tank to 0.5 bar for one minute. Use Test equipment for SCR system 99628. Look for reductant leaks in the double wall in the reductant pick-up unit hose.Check that the hose clamps on the tank pick-up unit are in the right place. Tighten or add new hose clamp. It is also possible to replace the tank pick-up unit with a new one with a thicker connection.Check whether the prefilter or the main filter is blocked.Make sure there is fuel in the tank. If there is fuel in the tank, the tank should be cleaned and the diaphragm pump, ventilating valve, and filter in the main unit should be renewed.Check whether there is fuel in the pump. If there is fuel in the pump, then the pump, gaskets, filter and ventilating valve must be renewed.Check the signal from the pressure sensor for the reductant.Check that heating of the reductant tank is working.Check that the reductant doser can close completely by running System checks 1–3.Fault code 4143 (EMS) may also be due to the valve plate in the pump expanding as a result of fuel. A deformed valve plate means that the pump fails to build up pressure. Check whether there is fuel in the filter.

Diagnostic depth