P2208
NOx Sensor Heater Sense Circuit Bank 1 Sensor 1
NOx sensor / emissions (SCR)
Generic OBD-II
Medium
What it means
P2208 indicates a fault in the heater sense circuit of the bank 1, sensor 1 NOx sensor — part of the emissions/SCR system that measures oxides of nitrogen in the exhaust. It usually starts as just a check-engine light, but on diesels an unresolved NOx sensor fault can eventually force a power derate, so it is worth addressing before it escalates.
Medium
Can I keep driving? Usually drivable at first, but on diesels a persistent NOx-sensor fault can trigger reduced power (derate) and emissions warnings, so don't ignore it.
Common symptoms
What you'll notice
- Check-engine light on
- Often no immediate driving symptoms
- Possible emissions/SCR warning message
- Reduced power or derate if the fault persists (diesel)
Common causes
Most likely first
- Faulty NOx sensor (bank 1, sensor 1)Likely
- Open or shorted NOx sensor heater sense wiringCommon
- Poor or corroded connection at the NOx sensorCommon
- Faulty NOx sensor control moduleLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame and check for companion NOx codes (P2209, P2210, P2211, P2200).
- Inspect the NOx sensor connector and harness for corrosion, heat damage, or a loose fit.
- Check the heater sense circuit for opens and shorts and confirm power and ground reach the sensor.
- Verify the NOx sensor module is powered and communicating on the data bus.
- If the wiring and connection are good, replace the NOx sensor and retest.
FAQ
Quick answers
Is it safe to drive with P2208?+
For short periods, usually. It is an emissions-monitoring fault, but on many diesels an unresolved NOx sensor fault can lead to a power derate, so have it repaired promptly.
Can I just clear P2208?+
It returns until the NOx sensor or its heater sense circuit is repaired, since the module continually monitors the sensor.
Related codes
Often seen with P2208
Read & clear P2208 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