Why is the urea fault light of China V diesel vehicle always on?
3 Answers
The urea fault light of China V diesel vehicle is always on due to lack of urea or loose sensor connection. Here is more relevant information: 1. The role of urea in vehicles: Vehicle urea is a diesel exhaust fluid that uses SCR (Selective Catalytic Reduction) technology to reduce nitrogen oxides in diesel vehicle exhaust. If the vehicle urea is missing or the SCR system malfunctions, the vehicle may exhibit symptoms such as weak acceleration, unresponsiveness to throttle, insufficient power, and inability to increase engine speed. 2. Specific solutions for urea faults: (1) If the vehicle shows symptoms of weak acceleration or white smoke from the exhaust pipe, professional equipment should be used to clean the urea crystallization in the exhaust pipe. (2) If the vehicle fault code indicates low urea pressure, urea should be replenished. (3) If the engine torque is limited and the speed cannot exceed 1800 rpm, the urea pump and sensor should be replaced.
Over the years of driving, the urea fault light on my China V diesel vehicle has come on quite a few times, mostly due to insufficient urea solution or poor quality. The China V standard requires urea injection to reduce exhaust pollution, and the light indicates an issue with the SCR system. The most common cause is an empty urea tank, which needs to be refilled promptly. Alternatively, the urea injector nozzle might be clogged due to road dust or impurities in the solution—cleaning it usually fixes the problem. Another possibility is a faulty sensor giving incorrect readings. If the light stays on and is ignored, the vehicle may experience torque limitation, reduced power, or even emit black smoke, increasing the risk of fines. Whenever I notice the light, I make it a habit to first buy genuine urea at a gas station and refill. If the light persists, I take it to a mechanic to scan for trouble codes. Additionally, urea tends to crystallize in cold weather, so freeze protection is important. In short, don’t delay—address it promptly to avoid breakdowns. Regular maintenance should also include attention to the urea system, using standard AdBlue during fluid changes to prevent issues.
China V diesel vehicles use urea to reduce nitrogen oxide emissions. The malfunction indicator light (MIL) coming on indicates system abnormalities. Start with simple checks: first verify if the urea tank level is insufficient - try refilling with standard-compliant AdBlue. If that doesn't work, potential issues could be: clogged urea injection pump or nozzle due to sediment buildup; or faulty sensors like NOx or temperature sensors sending erroneous signals. The system control module might also have bugs requiring reset or update. Persistent illumination of this light may trigger vehicle protection mode, such as limiting engine torque, resulting in poor driving performance. I recommend owners wear gloves and use basic tools to first inspect the urea tank cap and pipeline connections for leaks. If unresolved, professional diagnosis at a repair shop is necessary - never use substandard urea as it may corrode the system and worsen problems. Regular maintenance prevents issues - don't wait until exhaust emissions exceed standards to take action.
