Common Urea Pump Problems and Solutions: Ensuring Efficient Operation of Vehicle Emission Systems
With the continuous improvement of environmental standards, urea pumps (also known as AdBlue pumps) have become increasingly important in modern diesel engines. As a key component of the Selective Catalytic Reduction (SCR) system, the urea pump accurately injects urea solution into the exhaust system to reduce nitrogen oxide (NOx) emissions. However, many vehicle owners and fleet managers may encounter issues with urea pumps, which not only affect vehicle performance but also lead to SCR system failure, triggering engine fault warnings.
The issue of a urea pump not working is typically related to electrical problems. Common causes include a blown fuse, malfunctioning solenoid valve, or the ECU (Electronic Control Unit) not sending the correct signals. When encountering this issue, the first step is to check the power supply lines and electrical components to ensure they are functioning properly. If the power and wiring are in order, it is advisable to use professional diagnostic tools to check the ECU signals and replace any damaged control modules if necessary.
Low urea pump pressure is often caused by a clogged urea filter or damaged pump components (such as worn diaphragms or piston seals). This condition leads to insufficient urea solution injection, affecting the efficiency of the SCR system. Vehicle owners can resolve this issue by cleaning or replacing the urea filter. If the problem persists, it is recommended to inspect the pump's internal components and replace any damaged parts.
Urea pump leakage is a common issue. Leaks are typically caused by aging or damaged seals or loose connections in the pipelines. If a leak is detected, the vehicle owner should immediately check the seals and pipeline connections and replace any damaged parts. Additionally, urea crystallization can also lead to seal failure at connection points, so regular cleaning and maintenance are effective methods to prevent leakage.
Excessive noise from the urea pump may be caused by worn internal pump components or loose mounting brackets. Long-term overworking of the pump can also lead to excessive motor load, resulting in abnormal noise. To address this, the pump's mounting bracket should be inspected to ensure it is securely installed. Additionally, the pump's internal components should be checked, and any worn parts should be replaced.
In cold environments, urea solution is prone to crystallization, leading to blockages in the pump or pipelines. Crystallization buildup not only affects the normal operation of the urea pump but can also damage other critical components. Vehicle owners can prevent crystallization issues by activating the urea pump's heating function. Using high-quality urea solution and regularly cleaning the pipelines and pump are effective measures to prevent crystallization blockage.
Urea pump failure often triggers SCR system fault codes, with common codes including “P20E8” (urea pressure too low) and “P202E” (urea injection control failure). When encountering such issues, the vehicle owner should use an OBD-II scanner to read the fault codes and locate the source of the problem. Cleaning the urea pump and injectors and ensuring the urea solution meets the required quality standards typically resolves these issues.
The urea pump is an essential component in ensuring a vehicle meets emission standards. Regular maintenance and inspections, using high-quality urea solution, and maintaining a proper operating environment are the best ways to prevent urea pump failures. In the event of complex technical problems, timely consultation with professional repair technicians and the use of advanced diagnostic tools can ensure the efficient operation of the urea pump and the proper functioning of the vehicle’s emission system.
By keeping the urea pump in good working condition, vehicle owners can not only reduce emissions and prevent environmental pollution but also improve vehicle efficiency and reduce unnecessary repair costs.