Powertrain
generic / SAE
P22AA
NOx Sensor Heater Sense Circuit Intermittent (Bank 1 Sensor 2)
The feedback line that monitors the NOx sensor heater current draw on bank 1 sensor 2 jumps or drops out intermittently — connector loose or chafed wire near the exhaust heat zone.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number2 / AA
Possible causes
- Intermittent connector high
- Connector with intermittent contact under vibration low
- Harness routed against vibrating component 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: shop recommended
- Estimated cost: 80–700 €
- Estimated time: 0.5–3 h
- Component: nox sensor
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012