What is the SPN3226 fault?
2 Answers
SPN3226 fault code indicates that the emissions are not up to standard, and the urea supply system needs to be checked for proper functioning. Below is the relevant introduction: Origin of the name: The scientific name of automotive urea is Diesel Exhaust Fluid (DEF), commonly referred to in China as automotive urea, vehicle urea, or vehicle denitration agent. Automotive urea solution was first used in Europe, where it is called AdBlue, while in North America, it is known as DEF (Diesel Exhaust Fluid). It should be noted that there are urea production enterprises abroad that have AdBlue and DEF certifications, with strict international standards, while very few domestic enterprises in China can obtain AdBlue and DEF certifications. Composition materials: Automotive urea solution is a colorless, transparent, and clear liquid with a concentration of 31.8% to 33.2%, used for reducing NOx. Currently, the automotive urea solution in use is generally composed of 32.5% high-purity urea and 67.5% deionized water.
As an experienced long-haul truck driver, I dread seeing the SPN3226 fault code the most - it indicates a problem with the urea nozzle in the exhaust system. Once on the Yunnan-Guizhou expressway, I first noticed pungent exhaust fumes, then the truck gradually lost power until the engine limited output during climbs. The repair shop explained that a clogged urea system causes emission exceedance and can damage the expensive catalytic converter. You must immediately use a diagnostic tool to check whether it's a clogged nozzle, heating circuit issue, or failed urea pump - never push through. Last time I forced 200 kilometers with the issue, resulting in a 30,000+ RMB repair bill. Now whenever I detect abnormal smells, I stop immediately for inspection to avoid unnecessary expenses.
