Powertrain
generic / SAE
P220B
NOx Sensor Supply Voltage Circuit (Bank 1 Sensor 2)
The supply voltage rail to the NOx sensor on bank 1 sensor 2 is faulty — typically a fuse, harness break, or short. NOx sensors need a clean stable supply for the heater and the wide-band measurement cell.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number2 / 0B
Possible causes
- Supply rail fault high
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: 80–800 €
- Estimated time: 0.5–3 h
- Component: nox sensor
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012