OBD-II code · Powertrain (generic, extended)
P22A3 NOx Sensor Heater Control Circuit/Open (Bank 1 Sensor 2)
NOx Sensor Heater Control Circuit/Open (Bank 1 Sensor 2): the control circuit is open. The NOx sensor heater brings the sensor to operating temperature; a fault delays accurate NOx readings used for SCR control.
Is it safe to drive with P22A3?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyHeater winding open
- Less likelyPin pushed back out of connector body
- Less likelyCracked solder joint inside the module or sensor
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
- P2218NOx Sensor Heater Control Circuit/Open (Bank 2)
- P22A0NOx Sensor Circuit Low (Bank 1 Sensor 2)
- P22A1NOx Sensor Circuit High (Bank 1 Sensor 2)
- P22A2NOx Sensor Circuit Intermittent (Bank 1 Sensor 2)
- P22A4NOx Sensor Heater Control Circuit Low (Bank 1 Sensor 2)
- P22A5NOx Sensor Heater Control Circuit High (Bank 1 Sensor 2)
- P22A6NOx Sensor Heater Sense Circuit (Bank 1 Sensor 2)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.