P229E
NOx Sensor Circuit (Bank 1 Sensor 2)
NOx Sensor Circuit (Bank 1 Sensor 2): an electrical fault is present in the circuit.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
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.
- Sensor element failedCommon
Parts involved
- NOX Sensor
P229E 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.