Whenever a warning message or light appears on your dashboard, it signifies malfunctioning in any part of the vehicle. Sometimes, these warning messages are quite obvious that the driver understands quickly but some of the warning messages or error codes are so vague to understand and require proper diagnostic run to identify and fix the real problem. There could be various error codes pointing towards the similar solution. For example, following are some of the error codes that are showing different messages but all are pointing to the common problem with the emission system.
So, when any of these messages pop out on your dashboard, mainly the problem is with the NOx sensors or its heating element in the SCR system.
- P13400 The remaining driving distance is limited due to a malfunction in the AdBlue system.
- P13DF09 The AdBlue system has a malfunction. There is a component fault.
- P2BA901 The emission limit for the NOx concentration has been exceeded (Adblue quality is too low). There is a general electrical fault.
- P220E77 The heater of NOx sensor 1 (cylinder bank 1) has a malfunction. The commanded position cannot be reached.
- P22A677 The heater of NOx sensor 2 (cylinder bank 1) has an electrical fault. The commanded position cannot be reached.
- P22A7-00 P22A700 - Implausible Signal Intermittent NOx sensor 2 bank 1 heating circuit
- P22A1 NOx Sensor Circuit High Bank 1 Sensor 2
- P22A2 NOx Sensor Circuit Intermittent Bank 1 Sensor 2
- P22A3 NOx Sensor Heater Control Circuit/Open Bank 1 Sensor 2
- P22A4 NOx Sensor Heater Control Circuit Low Bank 1 Sensor 2
- P22A5 NOx Sensor Heater Control Circuit High Bank 1 Sensor 2
- P22A6 NOx Sensor Heater Sense Circuit Bank 1 Sensor 2
- P22A7 NOx Sensor Heater Sense Circuit Range/Performance Bank 1 Sensor 2
- P22A9 NOx Sensor Heater Sense Circuit High Bank 1 Sensor 2
- P220F NOx Sensor Heater Control - Circuit Range/Performance (Bank 1 Sensor 2)
- P229E NOx Sensor - Circuit Malfunction (Bank 1 Sensor 2)
Nox sensors and adblue system both are responsible for a clearer and environment friendly engine emissions so in this blog, we’re going to take a look at what the NOx sensor is, what is its purpose, what can commonly go wrong for it, and what the different kinds of error messages you’re likely to encounter, so you’re ready for any problem. Also, we will have some useful information on the role of NOx sensors heating element in the SCR system and how it contributes to the error- free drive.
Since NOX sensors are a requirement under the European Union emission laws that your engine emissions are safe for the environment and certified to EURO5 EURO6 etc, almost all car, truck, HGV, Lorries, tractors and others motor vehicle manufacturers including Audi VW Ford Citroen Peugeot Renault Dodge GMC GM Mack Chrysler Mopar Dorman Jeep Volvo DAF Iveco Cummins Duramax Isuzu Mercedes-Benz Porsche Land Rover Mazda Perkins Komatsu Caterpillar CAT Perkins John Deere Bosch Denso Delphi and Toyota are now installing NOx sensors as a standard equipment to comply with stringent environmental laws around the world.
In automotive industry, Bosch, Continental, Siemens VDO, NTK Japan are the main manufacturers and suppliers for NOx sensors and other different parts for emission system.
Most people are unaware that the AdBlue system on most cars uses the NOX sensor as an input to ascertain how much AdBlue is required to be injected to run a environment friendly drive and. Therefore, when your vehicle triggers P13DF09, P2BA901 or P13400 error codes, it specifically means that the adblue SCR emission control system in your Mercedes Benz has failed.
These 3 above mentioned diagnostic trouble codes are always triggered only when Nox sensor isn’t working properly as result, so it just say main cause is probe heater and in addition it explains that adblue system isn’t working anymore, you are exceeding Nox concentration etc.
Unfortunately, like any other electronic equipment, NOx sensors can be putrid over time and get malfunctioned, leading to a range of problems in your vehicle which may include reduced power, acceleration and performance. Once this NOx sensor causes trouble, you would most likely have the sensor replaced. If ignored, the problem could worsen, potentially costing you thousands of pounds to fix.
Possible symptoms and causes of NOx failure
NOx sensor is normally mounted on the exhaust system before the catalytic converter. The sensor measures the level of nitrogen oxide for the engine’s computer so adjusts valve timing and fuel mixture.
Most engines feature two NOx sensors: an upstream and another downstream sensor.
The first sensor (referred to as NOx sensor 1) is located near the turbo downpipe and measures engine out NOx. The second sensor (referred to as NOx sensor 2) measures NOx levels exiting the SCR catalyst. You may have noticed black smoke coming out of the engine exhaust or your car is not as economical on fuel.
Any fault in these 2 sensors will be shown as the following error codes.
- P220E77 The heater of NOx sensor 1 (cylinder bank 1) has a malfunction. The commanded position cannot be reached
- P22A677 The heater of NOx sensor 2 (cylinder bank 1) has an electrical fault. The commanded position cannot be reached
- P22A7-00 P22A700 - Implausible Signal Intermittent NOx sensor 2 bank 1 heating circuit
These 2 NOx sensors are located before and after the unit where adblue is added to the exhaust system to monitor the reduction in NOx content and the common causes of these sensors failure include soot build up on the sensor, ECU water intrusion and / or damage to the cable as well as false readings which will cause the check engine light to illuminate.
How to fix faulty NOX sensors?
P220E77 P22A677 codes mean that heater element inside the probe of Nox sensor has failed.
Replace nitrogen oxide (NOx) sensor also known as probe with a new NS11A Nox sensor probe or the entire NOx module with control unit and sensor.
As it is already noticed that different fault codes appear to highlight the failure of NOx sensor’s heater, you may find some other fault codes on GM, Chevy Vauxhall and Opel cars but the meaning of codes and error fixing will remain the same as mentioned in this blog, until definition of the code says that heater isn’t working properly.
Where to buy NOx sensors?
Replacing NOx sensors can be a DIY job, all you have to do is to buy the parts required for replacing NOx probe. We offer NS11A NOx sensor repair kit as well as other kits for NGK and NTK brands, heavy duty equipments, trucks, lorries, HGVs, Buses, tractors etc to assist you with the replacement of NOx probe.
