P2208

NOx Sensor Heater Sense Circuit Bank 1 Sensor 1

Q: 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.

Q: 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.

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.

Real-world scan data

Seen in

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

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.

Read & clear P2208 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX