Why doesn't the urea pump make noise after a China V vehicle is turned off?

[DeLondyn]

Reporting high urea pressure is usually caused by a blocked return check valve, which needs to be replaced with a new one. Below is relevant information about urea pumps: 1. Types: There are two types of urea pumps based on their internal structure. One is the airless urea pump represented by Bosch, and the other is the air-assisted urea pump represented by Emitec and Cummins. 2. Function: The working principle and internal structure of urea pumps The urea pump is the core component of the SCR system, known as the "urea metering pump." Its main function is to pump urea solution from the urea tank and transport it to the nozzle through delivery pipes.

[NorahAnn]

My family also owns a National V diesel vehicle, and we've encountered similar issues. If there's no sound from the urea pump after turning off the engine, there are actually several possibilities: either the pump itself is broken and not working; or there's poor contact in the wiring or a blown fuse; it could also be that the system is designed this way, not operating after shutdown, but most of the time it should make a slight sound for self-check. You should first simply check the fuse box, located in the engine compartment—open it to see if there are any blown fuses, and if so, try replacing one. If that doesn't work, then it's likely an issue with the pump or controller, and you'll need to take it to a repair shop for professional diagnostic tools. The emission system is not something to be taken lightly; if the urea pump is broken, the vehicle's exhaust emissions will exceed standards, affecting environmental protection and potentially causing it to fail the annual inspection. I recommend always using reputable brands when adding urea and avoid inferior quality ones, as they can easily clog the pump head.

[SavannahAnn]

As a seasoned driver with a decade of diesel vehicle experience, I've encountered situations where the urea pump remained inactive after engine shutdown. Typically, it's due to a blown fuse or a seized pump head. You can inspect the fuse box yourself to check if the urea pump's corresponding fuse is intact. If that's fine, then examine the wiring connectors for any looseness. The key point is, with China V emission standards relying on this SCR system to reduce emissions, a faulty pump significantly increases pollution. Once, my vehicle shook and threw a fault code, which turned out to be a defective pump that needed replacement. Regular maintenance should focus on urea fluid levels and quality—never let it run empty. Repairs aren't costly; usually, a 4S shop can diagnose it within half an hour. Don't delay—while safety risks are minor, the environmental impact is substantial.

[LiamLee]

As a tech enthusiast, I'm well aware of the SCR system in China V vehicles. The urea pump should emit a slight sound for self-check after shutdown, but if there's no sound, it could indicate pump failure, blown fuse, or circuit short. Digging deeper, the control module might also malfunction. During inspection, first check the fuse – its location is specified in the cabin or engine compartment manual. If all appears normal but the pump isn't working, poor urea quality might have caused crystallization blockage. China V emission standards impose strict NOx control, and pump issues can lead to excessive exhaust emissions. Regular system cleaning to prevent blockages and maintaining stable urea levels are recommended. Don't overlook minor faults.