How to troubleshoot the illuminated National V urea warning light?

[LaStella]

Methods to troubleshoot the illuminated National V urea warning light are as follows: 1. Symptoms of white smoke from the exhaust pipe: If the vehicle's exhaust pipe emits white smoke, professional equipment should be used to clean the urea crystallization inside the exhaust pipe. 2. If the vehicle's fault code indicates low urea pressure: When low urea pressure occurs, it is necessary to replenish the urea. If the engine torque is limited, the urea pump and sensor should be replaced. 3. Insufficient power: The warning light remains on, power is insufficient, torque is limited to 1800 rpm, and the SCR system cannot function properly. This situation occurs when urea consumption is either too high or too low.