AdBlue crystallization in the catalyst may in some circumstances occur when AdBlue is injected during cold cycles when the SCR catalyst is below the minimum temperature required for a chemical reaction. If the crystallization level becomes higher than what can be removed at normal engine operation, a regeneration may be necessary. This function is a procedure that can be forced by the diagnostic tool. The function burns particles present in the particle filter in order to clean it and the AdBlue crystals are converted to gas.
The exhaust temperature is very high during this procedure. Therefore, perform the regeneration outdoors without connected exhaust hose. The regeneration is noisy, use ear protection. The procedure lasts up to 30 - 90 minutes. The procedure shall be performed with warm engine. The coolant temperature must exceed 60°C.