P2206
NOx Sensor Circuit (Bank 2)
A general electrical fault on the bank 2 NOx sensor circuit. NOx sensors are smart sensors with a CAN/LIN interface; this code typically indicates that the sensor module no longer responds.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light or NOx warning on
- AdBlue/DEF level or quality warning
- Possible no-start countdown after ignore period
- Failed emissions inspection (NOx)
Common causes
Ordered by how often each turns out to be the cause.
- NOx sensor module failedCommon
- Wiring open or connector loosePossible
Parts involved
- NOX Sensor B2
- NOX Sensor Wiring
P2206 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.