Mercedes Benz in attempt to continuously improve its technology and striving to lessen its carbon footprint on environment and even achieving zero emissions through its fleet, taking huge steps to update ever-changing automotive industry. Mercedes Benz is a high-end vehicle brand which never compromises on the quality, brand image and customer satisfaction as well as safety. To reduce the impact of gases coming out of exhaust pipe of diesel cars, EPA emissions standards have made it necessary for all diesel car manufacturers to include BlueTec technology in exhaust system. Therefore, to make all newer models of Mercedes Benz, law compliant on roads BlueTec technology which utilizes AdBlue or Diesel Exhaust Fluid (DEF) to reduce NOx emissions has become a standard in its SCR (Selective Catalyst Reduction) system.
Many Mercedes-Benz diesel cars such as E220, C220, S350, G350, ML350, ML250 equipped with BlueTec technology use AdBlue® Diesel Exhaust Fluid (DEF) and provide great driving experience.
With BlueTec Technology, Mercedes Benz has been able to effectively reduce exhaust gas emissions while maintaining the performance of diesel engine at the same time. If you are a owner of Mercedes Benz it is necessary that you keep a check of adequate AdBlue levels in exhaust system to make your car legally compliant on the road. In case of failure to do so, there is a sheer possibility that you receive “Mercedes-Benz Cannot measure fluid level AdBlue” warning message on your dash board which means your car needs a AdBlue top up and no more legal on the road until the warning is removed.
To understand the function, effectiveness and necessity of using adBlue, it is good to have some basic information of SCR system, AdBlue and Nox Sensor.
What is SCR system?
SCR is an after treatment technology which is environment friendly and used to reduce emission levels. All the cars having SCR system are labeled or badged as “ BlueTec”. SCR system utilizes aqueous urea solution with de-ionised water to lessen the impact of harmful NOx emissions. This solution is called AdBlue which is injected into the exhaust gases of diesel engine as a post combustion process.
Where does adBlue goes into the exhaust system?
Mercedes benz genuine AdBlue goes into the vehicle adBlue tank which is separate from diesel fuel tank. To make it work efficiently, do not mix adBlue with water or any other additives to dilute this solution.
How often AdBlue needs to be refilled?
Insufficient levels of AdBlue hamper the performance of vehicle and operating your MB is not possible without it therefore the size of tank is usually designed in a way that refill requirement does not happen in between service intervals however depending on individual use, consumption may be higher. Under normal vehicle operating conditions, the AdBlue tank needs to be refilled only during regularly scheduled maintenance. 1 litre of adblue lasts for about 1000km on an average, but again,the consumption is largely dependent on the distance, driving and other conditions vehicle is subjected to.
If the amount of AdBlue® in the vehicle reaches the minimal level before an A or B Service, a message will appear on the instrument cluster.
Whenever such a message is visible on dashboard it is quite likely to have Engine Start not possible in x mi km error message as well.
Diagnosis for the error warning
To fix this malfunction, it is always recommended that you first need to perform a diagnostic run with the help of OB II scanner tool for diagnostic trouble codes (DTC) and find out which part in SCR system has failed because it is not necessary that only lower levels of adblue are responsible for indicating these errors. It could be an adBlue tank, blocked exhaust injector, complication with temperature or most commonly NOx sensor. To confirm your doubts, you must run diagnosis to address the actual faulty component.
It can be a complex area to work on when it comes to diagnosing problems but Xenons4u offers you support and guidance to find and solve issues.
In most of the cases, NOx sensors are responsible to limit the number of miles a car can be driven however there are a few symptoms other than diagnostic scanner to investigate further on likely chances of NOX failure.
Reasons of NOx failure:
Most common reasons which could indicate failure of NOx sensors are when:
- Fuel efficiency is reduced
- Excessive black smoke coming out from vehicle exhaust
- Engine performance diminishes
- Other SCR related codes appear
And sometimes, it may not be the NOx sensor itself it could be wirings that are damaged or loose.
Once you are confirmed it is NOx sensor, you need to immediately fix it within reasonable cost and convenience. There are usually two sensors; pre and post-cat NOx sensors. You need to check which one is at fault and then replace that one with a new NOx sensor. You can buy a repair kit only for the probe or a whole sensor including control unit to fix this error. Xenons4u provide all types of NOx sensors and all other vehicle components compatible with Mercedes Benz different models. Ideally the problem should be fixed and the error should disappear with the replacement of NOx sensor but if it does not then you may need to manually clear the codes in cluster. So, whenever you are presented with Mercedes Adblue level warning on your driver information display board, don’t ignore this because if your Mercedes Adblue tank runs empty, your vehicle will not start and you may stuck on the road.
