What are the reasons for a vehicle not consuming urea?

[LeVera]

Vehicle not consuming urea may be due to the SCR system not functioning properly. Below are the hazards of not using urea: 1. Environmental pollution: Diesel vehicles without urea can have an extremely negative impact on the ecological environment, and this is also prohibited by national laws and regulations. 2. Damage to the SCR injection system: If urea is not used for a long time, the nozzles, pipelines, and urea pump in the SCR system may crystallize and clog, or be damaged by high temperatures. 3. Reduced power: This is not a direct result of not using vehicle urea, but rather because when the engine's electronic control system detects no urea injection and excessive exhaust pollution, it will forcibly limit the engine's torque output.

[EmilyLynn]

My car is diesel-powered, and I've encountered the issue of not consuming urea several times, each time requiring some effort to diagnose. The most common cause is an empty urea tank—I often forget to refill it while driving, only realizing when the warning light comes on. Nozzle clogging is another headache, especially when using cheap or expired urea that leaves more residue. If the temperature sensor fails, the urea can freeze in cold weather or evaporate when too hot, affecting injection. A bug in the ECU software can also cause it to send incorrect commands, stopping the urea supply. Additionally, aging wiring with poor contact can lead to signal interruptions. The consequences of not consuming urea are significant: the engine automatically limits torque, reducing power, making it sluggish to drive, and emissions exceeding standards can lead to failed annual inspections. So, I make it a habit to check the urea level monthly, insist on buying reputable brands, store them in a cool place to avoid freezing, and promptly visit a specialized repair shop for diagnosis if any issues arise.

[ClaraRose]

I'm usually quite frugal and pay close attention to vehicle maintenance costs. I'm particularly wary of high repair expenses related to urea system failures. For example, replacing a faulty urea pump can cost hundreds or even thousands; cleaning clogged nozzles due to impurities might also incur high charges; sensor failures like thermometer malfunctions often require replacement. Additionally, ECU setting issues may need software upgrades, which can sometimes be costly at 4S shops. If left unrepaired, the vehicle may enter protection mode with limited speed, causing work delays and potentially damaging the aftertreatment system. I've tried using an OBD scanner to self-diagnose fault codes to save both money and time. For prevention, I only use qualified urea and refill it promptly to avoid running dry. Regular checks for loose pipe connections help prevent circuit breaks. In short, early detection and timely handling prevent major expenses.

[Guy]

I enjoy delving into automotive technology, and I've studied several mechanical reasons for urea-free operation. The core issues lie in the failure of the injection system components: nozzle clogging due to carbon buildup or foreign objects blocking the fluid path; the urea pump motor burning out, preventing pressurization; or temperature sensors malfunctioning, causing the ECU to misinterpret and halt operation. Additionally, short circuits or open circuits in the wiring can interrupt signal transmission. If these problems aren't resolved, the engine will limit torque, affecting driving performance. I often remind myself to use professional tools during maintenance to accurately diagnose trouble codes and address the root cause.