OBD code P2201

The bank 1 NOx sensor is reporting an out-of-range or implausible signal.

Estimated severity

Medium

Common symptoms

Check engine light on
Emissions or AdBlue warning
P20EE or P204F may also be present
Few driving symptoms at first
Possible limp mode if the SCR system is blocked by the fault

Likely causes

Faulty or aged NOx sensor
Wiring or connector damaged by heat or vibration
Exhaust leak before the sensor
Contamination from oil, coolant or excess soot
Real SCR problems generating out-of-range readings

Recommended checks

1. Identify whether the sensor is upstream or downstream of the SCR catalyst on that vehicle.
2. Check NOx sensor power, ground and communication.
3. Inspect wiring close to the exhaust for heat damage or rubbing.
4. Compare NOx readings with the engine warm and stable.
5. Check exhaust leaks and SCR codes before replacing the sensor.

What does code P2201 mean?

P2201 affects the NOx sensor used by the SCR system to control emissions. On Euro 6 diesel vehicles, an incorrect reading can cause AdBlue codes, wrong dosing, SCR efficiency faults or emissions warnings. The sensor works in harsh heat and contamination conditions.

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