What is the reason for the dashboard showing no urea when there is urea?
4 Answers
There are two main reasons for the urea warning light to come on: blockage of the urea pump and damage to the heating system. Warning light activation: If the vehicle's warning light comes on due to poor urea quality, it requires immediate inspection and diagnosis. Prolonged neglect may affect engine performance and even damage the urea pump. Dashboard display: The urea level is displayed in the vehicle's computer. The urea gauge symbol is very similar to the fuel gauge symbol, with the only difference being the addition of the word "ADBLUE" at the bottom. It is usually displayed as a percentage. If the vehicle's urea level is sufficient, the urea light will not illuminate. If the urea level is low, the vehicle will display a blue urea light on the dashboard, indicating that urea needs to be added promptly.
I encountered a similar issue last time—the dashboard kept showing a low DEF (Diesel Exhaust Fluid) warning even though there was plenty in the tank, which was really annoying. At the repair shop, the mechanic said the DEF level sensor might be clogged or miscalibrated. This sensor is located at the bottom of the DEF tank and reads the fluid level; if it gets dirty or worn out, it can give false readings. The mechanic used a diagnostic tool to check for trouble codes, which indicated poor sensor contact. After cleaning it didn’t work, so they replaced it with a new one, and that fixed the problem. Additionally, if the DEF pump nozzle gets crystallized and clogged, it can also affect the detection. I recommend using a pure DEF brand regularly to avoid impurity buildup. In short, don’t delay—head straight to a professional repair shop for a computer diagnosis, otherwise, you might face torque limitation issues that make driving unpleasant.
Among car enthusiasts, this issue is often discussed: the DEF tank is full, but the warning light indicates no fluid. There are various reasons, mostly due to sensor malfunctions, such as loose installation positions or oxidized wiring causing signal interruptions. It could also be internal system buildup, where the DEF pump connector is covered with crystals, preventing proper data transmission. The solution is to first check if the plugs and pipes are clean, or try resetting by disconnecting the power and restarting the ECU. In severe cases, replacing the sensor or pump assembly may be necessary. The cost isn't high, but the risk of driving delays is significant, so it's best to consult a mechanic as soon as possible.
False alarms for low urea levels in diesel vehicle dashboards are quite common, mainly due to faulty sensors: probes being contaminated or circuit short-circuits misleading the ECU's judgment. During maintenance, check the sensor's voltage value—only accurate if normal; if deviations are significant, clean or replace it. Additionally, poor urea quality can affect concentration detection, leading to system misjudgment. Preventive maintenance is crucial, including regular cleaning of system components.
