What Causes a Truck Not to Use Urea and How to Solve It?
2 Answers
A truck not using urea is generally due to issues such as a damaged urea pump, clogged urea lines, or blocked nozzles. These situations require timely inspection and repair at a professional auto repair shop. Below is some relevant information about vehicle urea: 1. Function: The primary purpose of using urea in vehicles is to reduce harmful nitrogen oxides in the exhaust into nitrogen and water. 2. Principle: The main harmful substances in exhaust are nitrogen oxides and particulates. While particulates can be reduced inside the engine through technical means, the exhaust mainly contains nitrogen oxides. By injecting urea into the exhaust after-treatment device, the urea decomposes into ammonia at high temperatures. Under the action of a catalyst, the ammonia reacts with nitrogen oxides to produce harmless nitrogen and water. This device is called the SCR after-treatment system.
I've been driving trucks for almost twenty years and have encountered this issue several times. The most common reason for a truck not using urea is a clogged urea injector or poor-quality urea, which prevents the system from functioning properly. It could also be due to a faulty sensor or poor wiring connections. As for solutions, start with a simple self-check: see if the urea level is sufficient, and if not, promptly add genuine urea solution. If the level is normal but the warning light remains on, it might be a clogged injector—try using a cleaning agent to flush it. If that doesn’t work, the safest option is to take it to a reliable repair shop. Last time my truck had this issue, I ignored it and ended up getting fined for excessive emissions, plus the engine consumed more fuel. To avoid trouble, make it a habit to use branded urea, never skimp on quality, and inspect the system every three months.