NOx Sensor Heater Sense Circuit Intermittent Bank 2
What it means
P2225 means the PCM saw an intermittent or erratic signal on the heater-sense circuit of the bank 2 NOx sensor. This circuit lets the computer confirm the sensor's heater is working so it can measure nitrogen-oxide levels. Because the fault is intermittent and emissions-related, the engine usually drives normally and the light may come and go. The most common cause of an intermittent code is a loose or corroded connector or chafed wiring rather than a fully failed part.
Can I keep driving? Drivable — an intermittent emissions fault, but on some diesels repeated NOx faults can lead to a speed-limiting derate, so track it down before it worsens.
Common symptoms
What you'll notice
- Check-engine light on, sometimes coming and going
- Often no noticeable change in how the car drives
- Failed or incomplete emissions readiness
- Possible DEF/SCR warning on diesel applications
Common causes
Most likely first
- Loose or corroded connector at the bank 2 NOx sensor (most common with intermittent faults)Likely
- Chafed or intermittently shorting heater-sense wiringCommon
- Poor ground for the NOx sensorCommon
- Faulty NOx sensor (internal heater-sense fault)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data to capture the conditions when the fault appears.
- Wiggle-test the NOx sensor connector and harness while watching live data — intermittent codes usually trace to a connection that breaks under vibration or heat.
- Inspect the harness for chafing or heat damage near the exhaust.
- Verify a clean ground for the sensor.
- Replace the NOx sensor if the heater-sense fault is internal. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2225?+
Can I just clear P2225?+
Related codes
Often seen with P2225
Read & clear P2225 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.