How to Confirm Urea Pump Failure?
3 Answers
If the urea pump motor produces a "buzzing" sound during rotation and limits the engine's power output, it can be confirmed that the urea pump is damaged. Below is relevant information about urea pumps: 1. Introduction: The urea pump is a crucial component of the urea solution injection metering system. Its primary function is to draw urea solution from the urea tank, maintain a certain pressure, and then deliver it to the injection unit to meet the flow and pressure requirements of the injection metering system. 2. Working Principle: The urea pump mainly consists of a motor, supply pump, return pump, switch valve, pressure chamber, throttle orifice, etc. The pump operates in two states: supply and emptying. When supplying liquid to the urea injection system, the motor drives the supply pump to transfer urea solution from the urea tank to the pressure chamber. A portion of the urea solution is used for injection, while another portion flows back to the urea tank through the throttle orifice.
When the urea pump in the car fails, I usually start by observing the warning lights on the dashboard—for instance, if the SCR fault light is on, that's a common signal. Then, I start the engine and listen for sounds; normally, the pump makes a slight humming noise when operating, but if it's broken, there might be no sound or unusual noises. Checking the urea tank fluid level is next—if it's depleting unusually fast or not at all, the pump might not be working. Then, by smelling, a functioning urea pump has a slight ammonia odor, but an excessive smell could indicate a leak or damage. Finally, a simple pressure test can be done by opening the fuel filler cap to see if too much gas is escaping from the exhaust port. These everyday methods can help you make a preliminary diagnosis without spending a penny, identifying issues to avoid driving with excessive emissions and getting fined. Remember to get it repaired promptly, or it could affect the exhaust treatment system.
To confirm if the urea pump is faulty, I believe using a diagnostic tool is the most reliable method. Connect to the vehicle's OBD port, grab a universal scanner or a mobile app, and read the fault codes. If it starts with a 'P', like P204F, it directly points to the issue. At the same time, observe the urea system status—normal pressure should be within the standard range. During regular use, I've noticed that sudden increases or decreases in urea consumption, abnormal noise levels from the pump (either too loud or too quiet), are all signs of damage. Additionally, if the emission warning light on the dashboard lights up, it also indicates trouble with the pump. These simple steps are easy to follow, allowing you to DIY and avoid being overcharged at repair shops, protecting both your wallet and your vehicle's environmental performance.
