Why is the urea fault light on in a new car?

[VonAlessandra]

The urea fault light in a new car comes on due to reasons such as depleted urea solution, substandard urea quality, or blockage in the SCR system pipelines. Here are more details: 1. Specific solutions for urea faults: (1) If the vehicle exhibits symptoms like poor acceleration or white smoke from the exhaust pipe, 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, the urea solution needs to be replenished. 2. Automobile urea: Automobile urea is a diesel exhaust fluid that uses SCR (Selective Catalytic Reduction) technology to reduce nitrogen oxides in diesel vehicle emissions. If the automobile urea is missing or the SCR system malfunctions, the vehicle may show symptoms like poor acceleration, unresponsiveness to throttle, insufficient power, or inability to increase engine RPM.

[LaAna]

I just dealt with this annoying issue recently - never ignore the urea warning light on a new car. Last time when I was driving on the highway, the light suddenly came on, which really made me nervous. At the 4S店, they plugged in the diagnostic computer and found it was a false alarm from the urea level sensor - new car sensors are overly sensitive and can trigger false alarms even from minor water splashes during urea refills. The mechanic told me this is the most common issue with China VI emission standard vehicles, usually caused by either poor-quality urea clogging the injector or loose wiring connections in the after-treatment system. By the way, those small jerrycans of automotive urea sold at gas stations may be cheap, but the quality is really subpar. I switched to big-brand barrel urea instead, and after driving a few dozen kilometers, the fault code cleared by itself.

[OAubrey]

As a veteran driver frequently involved in logistics, I've seen too many issues with new truck urea systems. Focus on checking three key areas: whether the urea tank level is below 20%—poor-quality urea crystallization can clog the sensor probe; whether the NOx sensor on the exhaust pipe is corroded by moisture (this part costs several thousand); and the most troublesome issue—urea pump blockage, especially in northern winters when the wrong antifreeze-grade urea is used. Urea rated for -11°C can freeze solid at -15°C. After starting the engine, it's recommended to press the accelerator deeply a few times to raise the exhaust temperature above 300°C for self-cleaning. If the warning light remains on, promptly reset it with a diagnostic tool.

[VanJuliana]

Last week, my neighbor's daughter panicked when her new car's yellow warning light came on after only 2,000 kilometers. Actually, it's just a three-step check: First, see if the dashboard urea level display is normal—new cars often have delayed level readings. Next, smell the exhaust; if there's a pungent ammonia odor, it usually means the nozzle is leaking. Finally, listen for sounds—the urea pump should make a clicking noise when working; no sound indicates an electrical issue. Nowadays, dealerships have deep tricks, often pushing for a full aftertreatment system replacement, when 80% of the time it's just a loose connector. Remember, don't wait for the fuel tank light to come on before adding urea—fluctuating levels damage the pump the most.