Technical Description of OBD-II Trouble Code
Low Bank 1 NOx Sensor Heater Sense Circuit
What does that signify?
This is a standard diagnostic trouble code (DTC) for powertrain issues that typically applies to OBD-II vehicles. Vehicle makes that may be affected include Mercedes-Benz, Sprinter, VW, Audi, Ford, Dodge, Ram, Jeep, etc.
NOx (Oxides of Nitrogen) sensors are primarily used in diesel engines for emission systems. Their main purpose is to detect NOx levels in the exhaust after combustion in the engine. The system then recycles these emissions using various methods. Due to the harsh environment, these sensors are made of a combination of ceramic and a specific type of zirconia.
One of the negative impacts of emitting NOx into the atmosphere is the potential for smog and acid rain. Failure to monitor and adjust NOx levels properly can have a significant effect on the air we breathe and the environment. The Engine Control Module (ECM) continuously monitors the NOx sensors to ensure acceptable emissions levels in the vehicle’s exhaust.
The ECM calculates the levels of Nitric Oxide and Nitrogen Dioxide gases (NOx) by using data from the upstream and downstream oxygen sensors, along with the NOx sensor readings. This is done to regulate the NOx levels emitted from the tailpipe for environmental reasons. The Bank 1 mentioned in this trouble code refers to the engine bank that contains the #1 cylinder.
P2210 is the code that indicates “Low Bank 1 NOx Sensor Heater Sense Circuit”. This code appears when the ECM detects an issue with the output level from this circuit. The readings from the circuit are too low compared to the desired specifications.
It is important to allow the system to cool before working on any exhaust system components, as diesel engines generate a significant amount of heat.
An example of a NOx sensor (in this case, for GM vehicles):
What is the severity of this DTC?
If the trouble codes are ignored and no action is taken to repair them, it could lead to catalytic converter failure. Ignoring the symptoms and causes of these trouble codes can result in further complications for the car, such as consistent stalling and reduced fuel economy. If you notice any of the potential symptoms listed below, it is highly recommended to have the issue checked by a professional.
What are some of the symptoms of the code?
Symptoms of a P2210 diagnostic code may include:
What are some of the common causes of the code?
Possible causes for this P2210 NOx sensor code may include:
What are some P2210 diagnostic and troubleshooting steps?
The first step in troubleshooting any malfunction is to research the Technical Service Bulletins (TSB) for known issues with the specific vehicle.
Advanced diagnostic steps are highly vehicle specific and may require specialized equipment and knowledge for accurate performance. The basic steps provided below should be supplemented with a vehicle year/make/model/powertrain specific repair guide for precise instructions.
Basic Step #1
The initial step should always be to clear the codes and re-scan the vehicle. If none of the Diagnostic Trouble Codes (DTCs) appear as active immediately, take the vehicle for a lengthy multi-stop test drive to see if they reappear. If only one of the codes is reactivated by the ECM, continue the diagnostic process for that specific code.
Basic Step #2
Next, check the exhaust system for any leaks. Black soot around cracks and/or gaskets indicates a leak. Address this issue accordingly, as replacing an exhaust gasket is usually a straightforward task. A fully sealed exhaust system is crucial for the proper functioning of the sensors involved.
Basic Step #3
Using an infrared temperature gun, monitor the temperature of the exhaust before and after the catalytic converter. Compare the results to the manufacturer’s specifications, referring to the specific service manual for guidance.
Basic Step #4
If the catalytic converter temperature is within the specified range, focus on the electrical system associated with these sensors. Start with the harness and connector of the bank 1 NOx sensor. These harnesses often crack and fail due to the extreme temperatures near the exhaust. Repair any damaged wires by soldering the connections and using heat shrink tubing. Also inspect the oxygen sensors involved in bank 1 to ensure they are not damaged, as this can affect the downstream NOx readings. Repair any connectors that are not making sufficient connections or not locking properly.
This article is intended for informational purposes only, and the technical data and service bulletins specific to your vehicle should always take precedence.
