Back in 2010, to make your vehicle environment friendly and compliant with federal regulations on vehicle emissions, diesel-run vehicles has been mandated to use SCR Selective catalytic reduction system in diesel engines to reduce pollution output to the lowest level. EPA emissions standard required the use of a chemical named as DEF or Adblue which works with catalytic converter to convert harmful emissions into harmless contents for the environment. Adblue is alternative name for DEF used as trade name in many parts of the world and modern technology has quickly adapted to DEF's role in our lives. Vehicles with SCR technology have warning message displays on their dashboard that can easily alert the driver regarding DEF levels.
Low mileage or engine not restart messages are likely to be displayed when either DEF/Adblue levels are too low or SCR system experience any fault with any of its other component. Ignoring the warning light or messages on your dashboard does not pay off because if you run out of AdBlue while driving, your car’s performance will likely be affected as it tries to reduce its emissions output.
What is DEF?
Although, DEF or Adblue may be new to some motorist but owners of diesel engines that are compliant with euro 6 standards are already familiar with it. Basically, DEF is a non-toxic, colorless chemical combination of de-ionized water and pure urea that transforms harmful nitrous oxide emissions into harmless water and simple nitrogen gas. Without DEF/ Adblue, it would be much difficult to lower the emissions of diesel cars and get them to comply with latest standards.
How does it work?
The selective catalytic reduction, or SCR, technology is employed which involves injecting precise amounts of DEF liquid into the vehicle exhaust gases. When this solution combines with exhaust gases, it produces a chemical reaction which breaks down and neutralises harmful emissions from diesel exhaust. This technology has been used in buses and heavy Lorries for a long time, so its effectiveness has been proven and its reliability is better than ever so you should never run out of the required levels of DEF in your vehicle.
How to avoid DEF/Adblue warning messages?
Depending on the usage of car, all diesel cars that use AdBlue will give you plenty of warning that you're running low and needs a top up but once you’ve stopped, the majority of modern cars cannot be restarted if the AdBlue tank is empty. Fortunately, this situation is easily avoidable, as AdBlue DEF refills are straightforward available and usually relatively cheap if you shop around and do them yourself. You should refer to owner’s manual instruction on how to access and refill the tank.
Ideally, your DEF/Adblue levels must be checked and topped up at every service or at times when required. But this is rarely the cheapest option.
Adblue Pump stations are the best location to top up your Adblue DEF from. In the same way that diesel fuel is fundamentally the same from one retailer to another, make sure that AdBlue meets the correct specifications of your vehicle as one brand of AdBlue should be pretty much the same as another, so look for ISO number when buying one for your car.
What could be other reasons for this warning?
However, sometimes you might receive warning message on your dashboard saying “Engine Will Not Restart in X Mi KM Service DEF See Dealer” even with a filled tank. So, there could be a problem with components of SCR system such as NOx sensor, DEF pump injector or sometimes the nozzle can be culprit which limits the flow of enough DEF into exhaust.
DEF nozzle or injector pump can be blocked or damaged by the crystallization formed on it from DEF fluid and can suffocate the performance of your diesel engine by not pumping and injecting enough DEF fluid into the exhaust system.
Cleaning these parts and clearing the code should give vent to this problem in some conditions where blockage is not very much and crystallization formed can easily be removed; but if cleaning is not possible and the error persists, then you should consider replacing DEF (Adblue) injector pump and nozzle to further damage efficiency of your engine and to avoid your carbon footprint.
This kind of warning message is the most common in GM group SUVs such as Jeep Chrysler GMC Dodge RAM1500 with cummins engine.
Replacing these parts will guarantee performance efficiency of your vehicle so it is really important that you contact your dealer for a help in buying right components with correct specifications for your vehicle and bring your vehicle back in ideal condition.
