How to Deal with Urea System Failure Exceeding 50 Kilometers?
3 Answers
Usually, an early warning value is set for the urea level. When the urea solution falls below the alarm value, the system will restart the engine. Until the set number is reached, adding urea can release it.
Last time my urea warning light came on, I stubbornly drove another 100 kilometers, and ended up paying 8,000 bucks for repairs. Now I'm telling you from the bottom of my heart: when that warning light comes on, immediately slow down to under 60 km/h! First, turn on your hazard lights and pull over, then disconnect the negative battery terminal for ten minutes before reconnecting it—this trick can temporarily remove the torque limitation. But whatever you do, don't drive more than 20 kilometers—the urea nozzle can clog up like a concrete pillar, and the SCR catalyst can melt, forcing you to replace the entire exhaust system. The worst case I've seen was the complete failure of the aftertreatment system, with repair costs hitting 48,000, more expensive than the truck itself. Call a tow truck to the service station right away. On the way, you can try flushing the nozzle with bottled water as an emergency measure, but the key is to have the mechanic use a diagnostic tool to check whether the fault code originates from the pump or a sensor issue.
Buddy, you're really pushing your luck driving like this! In my 11 years as a mechanic, I've seen too many urea systems fail: if you drive over 50 kilometers, the ECU will permanently lock the torque, and you won't go faster than 40 km/h even with the pedal to the metal. The most critical issue is that the DPF particulate filter will clog up, and once the turtle warning light pops up on the dashboard, you'll have no choice but to call a tow truck. Quickly open the urea tank lid and check for an ammonia smell—if there's no smell, it means the injection has completely stopped. As an emergency workaround, you can disconnect the urea pump connector and use a zip tie to fix the exhaust temperature sensor at the 500-degree position, but this trick will only last for about 30 kilometers. My advice is to get off the highway right now and search for the nearest diesel vehicle specialist repair shop on Gaode Maps—don't trust regular repair shops to handle this issue.
