P2224
NOx Sensor Heater Sense Circuit High Bank 2
NOx / SCR emissions
Generic OBD-II
Medium
What it means
P2224 means the ECM detects high voltage in the heater sense circuit of the bank 2 NOx sensor. The heater brings the sensor up to operating temperature so it can measure nitrogen oxides for the SCR/emissions system. This is an electrical fault, typically the sensor's heater, its connector, or the circuit wiring, rather than an engine-running problem.
Medium
Can I keep driving? Usually driveable; it's an emissions-monitoring fault, though on diesels a persistent NOx-sensor problem can lead to a DEF/SCR warning, so get it checked.
Common symptoms
What you'll notice
- Check-engine light on
- Slow NOx sensor readiness or incomplete emissions monitor
- Possible SCR/DEF warning on diesels
- Higher emissions
Common causes
Most likely first
- Faulty NOx sensor or its heater element (bank 2)Likely
- Open or short-to-voltage in the heater sense circuit wiringCommon
- Poor or corroded connector at the sensorCommon
- NOx sensor module or PCM fault (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data, then inspect the NOx sensor connector and heater-circuit wiring for opens or shorts to power.
- Check the heater supply and ground.
- Test the sensor and heater resistance per the service data.
- Replace the NOx sensor if the heater circuit is at fault.
- Clear the code and retest.
FAQ
Quick answers
Is it safe to drive with P2224?+
Generally yes. It's an electrical fault in the sensor's heater circuit that affects emissions monitoring, not engine running. Repair it so emissions readiness can complete and to avoid an SCR warning.
Can I just clear P2224?+
You can, but it returns if the heater circuit or sensor is faulty. Fix the electrical problem first.
Related codes
Often seen with P2224
Read & clear P2224 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX