09-03-2025
6 min.
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P2213 NOx Sensor Circuit Malfunction (Bank 2)

P2213 NOx Sensor Circuit Malfunction (Bank 2) is a generic OBD-II diagnostic trouble code that indicates the Engine Control Module (ECM) has detected a malfunction in the NOx sensor circuit on Bank 2.

The NOx sensor is an important component of modern emission control systems, especially in diesel vehicles equipped with Selective Catalytic Reduction (SCR) technology. It measures the amount of nitrogen oxide (NOx) in the exhaust gases and sends this information to the ECM to control systems such as DEF (Diesel Exhaust Fluid/AdBlue) injection and exhaust emission management.

When the ECM detects that the NOx sensor circuit is not operating correctly, it stores the P2213 fault code and usually activates the Check Engine Light.

What Does P2213 NOx Sensor Circuit Malfunction (Bank 2) Mean?

The NOx sensor monitors nitrogen oxide levels in the exhaust system. These measurements are essential for reducing harmful emissions and ensuring that the vehicle meets emission regulations.

Modern diesel engines use NOx sensors together with:

SCR catalytic converters
DEF/AdBlue injection systems
Exhaust temperature sensors
EGR systems
Engine control modules

The ECM constantly monitors the NOx sensor circuit to verify that the sensor is receiving proper power, communicating correctly, and providing accurate data.

The P2213 code indicates that the ECM has detected a problem with the NOx sensor circuit. The problem may be caused by the sensor itself, electrical wiring, connectors, communication problems, or related emission system components.

Bank 2 explained

Bank 2 refers to the side of the engine that does not contain cylinder number one. On engines with two cylinder banks, such as V6 and V8 engines, the ECM separates sensor locations by Bank 1 and Bank 2.

What Does the NOx Sensor Do?

The NOx sensor measures nitrogen oxide levels in exhaust gases.

Nitrogen oxides are harmful pollutants created during the combustion process, especially in diesel engines operating at high temperatures.

The NOx sensor helps the vehicle:

Monitor exhaust emissions
Control DEF injection
Improve SCR efficiency
Reduce nitrogen oxide emissions
Maintain emission compliance

A faulty NOx sensor can cause the ECM to receive incorrect information, which may affect the entire emission control strategy.

P2213 Symptoms

The symptoms of P2213 may vary depending on the vehicle manufacturer and the severity of the circuit problem.

Common symptoms include:

Check Engine Light

The most common symptom is an illuminated Check Engine Light. The ECM activates the warning light when it detects an abnormal NOx sensor circuit condition.

Emissions system warning

Many diesel vehicles may display messages such as:

Emissions System Fault
Exhaust System Malfunction
AdBlue/DEF System Fault
Engine Management Warning

Reduced engine performance

Some vehicles may activate a protection mode to prevent excessive emissions.

Possible effects include:

Reduced engine power
Limited acceleration
Reduced torque output

SCR system malfunction

Because the NOx sensor provides information for SCR operation, a faulty circuit can affect DEF injection and catalyst efficiency.

Increased DEF/AdBlue consumption

Incorrect NOx readings may cause the vehicle to inject more DEF than necessary.

Higher emissions

The vehicle may produce higher NOx emissions because the emission control system cannot operate correctly.

Failed emissions inspection

A vehicle with an active P2213 fault may fail emissions testing.

Common Causes of P2213

Several problems can trigger the P2213 NOx Sensor Circuit Malfunction code.

Faulty NOx sensor

A failed NOx sensor is one of the most common causes.

Possible internal failures include:

Electronic component failure
Sensor communication failure
Internal circuit damage
Heater-related problems
Incorrect NOx readings

NOx sensors operate in a very hot exhaust environment, which can shorten their service life.

Damaged wiring harness

The NOx sensor wiring is located close to the exhaust system, where it is exposed to extreme temperatures.

Common wiring problems include:

Melted insulation
Broken wires
Short circuits
Heat damage
Wire corrosion

Electrical connector problems

Poor electrical connections can interrupt communication between the NOx sensor and ECM.

Possible issues include:

Corroded terminals
Loose connectors
Damaged pins
Moisture contamination

Power supply or ground problems

The NOx sensor requires stable electrical power and proper grounding.

Possible causes:

Blown fuse
Weak ground connection
Low voltage supply
Damaged power wiring

Faulty NOx sensor control module

Some vehicles use a separate NOx sensor control module.

A failed module can cause:

Communication problems
Incorrect sensor readings
Heater control issues
Circuit errors

Exhaust system problems

Although the circuit itself may be working, exhaust-related problems can affect NOx sensor operation.

Possible causes:

Exhaust leaks
SCR system faults
DEF injection problems
Excessive soot buildup

ECM problems

ECM failure is rare, but possible.

Potential issues include:

Internal circuit failure
Software problems
Communication errors

Vehicles Commonly Affected by P2213

P2213 is commonly found on diesel vehicles equipped with advanced emission control systems.

Examples include:

Mercedes-Benz

BlueTEC diesel models
OM651 and OM642 diesel engines

BMW

BMW diesel models equipped with SCR systems

Volkswagen / Audi

TDI diesel engines

Ford

Power Stroke diesel engines

General Motors

Duramax diesel engines in Chevrolet and GMC models

Ram

Cummins diesel engines

Jeep

EcoDiesel models

Land Rover

Modern diesel vehicles with SCR systems

Volvo

Diesel vehicles using NOx monitoring systems

The exact cause and repair procedure depend on the vehicle model, engine type, and emission system design.

How Is P2213 Diagnosed?

Correct diagnosis requires checking the complete NOx sensor system.

Scan for additional fault codes

A technician should first check for related codes involving:

NOx sensors
SCR system
DEF system
Exhaust temperature sensors
EGR system
Communication networks

Additional codes can help identify whether the problem is electrical or emission-related.

Inspect the NOx sensor

The sensor should be checked for:

Physical damage
Exhaust heat damage
Corrosion
Incorrect installation

Inspect wiring and connectors

The complete wiring system should be checked for:

Broken wires
Melted insulation
Loose connectors
Corroded terminals
Short circuits

Test electrical circuits

Technicians should verify:

Power supply voltage
Ground connection
Signal communication
Circuit continuity

Check live data

A diagnostic scan tool can monitor:

NOx sensor readings
Sensor communication status
SCR operation
DEF injection data

Inspect the exhaust system

The exhaust system should be checked for:

Leaks
SCR catalyst problems
DEF system faults
Incorrect exhaust temperatures

How Is P2213 Fixed?

The repair depends on the actual cause of the fault.

Replace the NOx sensor

If the sensor has internal failure, replacement is required.

Repair damaged wiring

If wiring problems are found:

Damaged wires are repaired
Broken sections are replaced
Insulation damage is corrected

Repair electrical connectors

Possible repairs include:

Cleaning corrosion
Replacing damaged connectors
Repairing connector pins
Improving electrical contact

Repair power and ground problems

Electrical supply issues must be corrected before replacing components.

Replace NOx sensor control module

If the vehicle uses a separate control module and it has failed, replacement may be required.

Repair SCR or DEF system problems

If the NOx sensor problem is caused by emission system issues, those problems must also be corrected.

Update vehicle software

Some vehicles may require ECM or NOx module software updates.

After repair:

Clear the fault code
Perform a drive cycle
Check NOx sensor operation
Confirm that the code does not return

Can You Drive With P2213?

It may be possible to drive with P2213 for a short time, but ignoring the problem is not recommended.

Possible consequences include:

Increased emissions
Reduced SCR efficiency
Increased DEF consumption
Reduced engine performance
Possible limp mode activation

For diesel vehicles, fixing emission-related faults early can prevent additional system problems.

Is P2213 a Serious Code?

P2213 is considered a moderate to serious diagnostic trouble code because it affects the vehicle's emission control system.

The vehicle may continue running normally, but the ECM may not be able to correctly control:

NOx reduction
DEF injection
SCR operation

Ignoring the problem may lead to:

Poor emission performance
Reduced fuel efficiency
Additional emission system faults
Failed inspection results

How to Prevent P2213

Regular maintenance can help prevent NOx sensor circuit problems.

Recommended practices include:

Inspect exhaust wiring regularly

Heat damage near the exhaust system should be repaired immediately.

Keep electrical connectors clean

Protect connectors from:

Water
Dirt
Corrosion

Maintain the SCR system

Use correct DEF/AdBlue and follow manufacturer maintenance recommendations.

Repair exhaust leaks quickly

Exhaust leaks can affect sensor readings and emission system operation.

Do not ignore warning lights

Early diagnosis can prevent more expensive emission system problems.

Final Thoughts

P2213 NOx Sensor Circuit Malfunction (Bank 2) indicates that the ECM has detected a problem with the electrical circuit of the Bank 2 NOx sensor.

The most common causes include:

Failed NOx sensor
Damaged wiring
Connector problems
Power supply issues
NOx control module failure
SCR or DEF system problems

A complete inspection of the NOx sensor, wiring, connectors, control module, and emission system is necessary to identify the real cause and restore proper vehicle operation.