Drive a C3 Aircross Diesel 1.6Blue Hdi; 120 hp. At 78000km mileage, the AdBlue warning light went on the highway and gave the above mentioned warning. At the next petrol station immediately stock Adblue checked and refilled 10 liters. When the bonnet was opened a very strong amoniacal odor was removable., also the catalyst side in the area of the AdBlue injection nozzle was covered with white covering, Here is probably a leak, which leads to false exhaust gas values. A total of 3 Citroen workshops in order to have the fault memory read out and to set a probably necessary repair date. At all workshops a short-term readout of the fault memory is not possible, earliest repair date middle to end of May. Injection nozzle AdBlue currently not available. Could order an injection nozzle via Internet ( at the price between 80 and 120 € ) and have it installed in a workshop of my confidence, which is only useful, however, who the AdBlue pump is not the cause of the leak on the injection valve due to too high pressure (pressure limitation valve). My question, someone has already had the same problem of you here, and how has it been solved.