OBD-II code · Powertrain (generic, extended)
P22A0 NOx Sensor Circuit Low (Bank 1 Sensor 2)
NOx Sensor Circuit Low (Bank 1 Sensor 2): the signal voltage is below the expected range. Often a short to ground or high resistance in the wiring.
Is it safe to drive with P22A0?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyShort to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
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)
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–3 h
- Emissions test
- Likely to fail
- Parts involved
- Nox Sensor
Related codes
- P2215NOx Sensor Circuit Low (Bank 2)
- P229DFuel Pressure Regulator B Exceeded Learning Limits - Too High
- P229ENOx Sensor Circuit (Bank 1 Sensor 2)
- P229FNOx Sensor Circuit Range/Performance Bank 1 Sensor 2
- P22A1NOx Sensor Circuit High (Bank 1 Sensor 2)
- P22A2NOx Sensor Circuit Intermittent (Bank 1 Sensor 2)
- P22A3NOx Sensor Heater Control Circuit/Open (Bank 1 Sensor 2)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.