Powertrain
generic / SAE
P2209
NOx Sensor Heater Sense Circuit Range/Performance (Bank 2)
The heater feedback (sense) line on the bank 2 NOx sensor reports values outside the expected window — heating is happening but the temperature does not match the model.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number2 / 09
Possible causes
- Heater element ageing, resistance drift high
- Sensor module failed medium
- Sensor element aged beyond calibration window low
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)
Inspection / repair
- Difficulty: medium
- DIY: possible
- Estimated cost: 300–1000 €
- Estimated time: 0.5–2 h
- Component: nox sensor b2
- Component: nox sensor heater
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012