NOx Sensor Heater Sense Circuit Range/Performance Bank 2
What it means
P2222 means the heater sense circuit for the bank 2 NOx sensor is reading outside its expected range. The heater warms the sensor to operating temperature so it can accurately measure nitrogen-oxide levels for the emissions system. An out-of-range reading usually traces to the sensor's heater element, its wiring, or a poor connection. The engine still runs, but emissions monitoring is compromised and it should be repaired.
Can I keep driving? Usually driveable — this is an emissions-monitoring fault — but it will fail emissions and some diesels may derate, so have it repaired.
Common symptoms
What you'll notice
- Check-engine light on
- NOx sensor not reaching correct operating readiness / emissions-test failure
- Possible SCR/DEF warning on diesels
- Often no obvious drivability change
Common causes
Most likely first
- Faulty bank 2 NOx sensor heater elementLikely
- Open, shorted, or high-resistance wiring in the heater sense circuitCommon
- Poor or corroded connector at the sensorCommon
- Faulty NOx sensor control module — rareLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and inspect the bank 2 NOx sensor connector and wiring for corrosion, damage, or high resistance.
- Check the heater sense circuit's voltage and continuity against spec.
- Confirm the sensor's power and ground are within range.
- Replace the bank 2 NOx sensor if the heater sense reading stays out of range with good wiring.
FAQ
Quick answers
Is it safe to drive with P2222?+
Can I just clear P2222?+
Related codes
Often seen with P2222
Read & clear P2222 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.