How to Resolve the AdBlue Warning Light?
2 Answers
AdBlue is a diesel exhaust fluid, also known as automotive environmental urea. When the AdBlue warning light appears on the instrument cluster, it is necessary to check and replenish the urea. Some vehicles may fail to start after running out of urea. Once the warning light comes on, urea should be added immediately. For most vehicles, the light will turn off after driving a certain distance following the urea replenishment. Adding urea to diesel vehicles is aimed at reducing exhaust emissions and protecting the atmospheric environment. The use of urea in vehicles helps convert harmful nitrogen oxides in the exhaust into nitrogen and water. Diesel vehicles equipped with a urea system require a urea tank to store the urea liquid. The ECU calculates the theoretical amount of nitrogen oxides generated based on engine speed, fuel injection volume, and other data. It then determines the required amount of ammonia to treat these nitrogen oxides based on the chemical reaction ratio, subsequently calculating the necessary urea injection volume. The system then controls the injection system to spray urea into the high-temperature exhaust gases at the exhaust end to eliminate nitrogen oxides.
I've encountered the AdBlue light coming on a few times while driving, and the most common reason is the urea solution level being too low. Diesel vehicle emission systems require AdBlue to reduce nitrogen oxides, and when the level is low, the dashboard will illuminate a warning light. You can handle it yourself: find a gas station or auto parts store to buy a can of AdBlue, usually 10 or 20 liters, open the trunk to locate the blue filler cap, and slowly pour it in until full. After filling, start the car and drive about 50 kilometers, and the light should automatically turn off. If it remains on, it might be due to a dirty sensor or system malfunction—clean the filler port or read the fault codes. Don't delay too long; I once forgot to deal with it, and the system mistakenly thought it was low on fluid and limited the starting speed, which was quite troublesome. It's advisable to check the AdBlue level regularly when refueling and keep it above medium to save a lot of hassle. Wear gloves when refilling to avoid skin contact, and wipe up any spills immediately to prevent corrosion.
