What it means
NOx Sensor Heater Sense Circuit Range/Performance (Bank 2): the signal is implausible or outside the valid range. The NOx sensor heater brings the sensor to operating temperature; a fault delays accurate NOx readings used for SCR control.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The bank 2 NOx sensor heater sense circuit reports heater behavior to the control module, which checks that signal for plausibility. This code sets when the signal is outside its valid range or does not behave as expected, even if it is not simply stuck high or low.
Common causes
Most likely first.
- Sense circuit drift
- Sensor element aged beyond calibration window
- Sensor mounting loose - signal damping
Symptoms
- Check engine light or NOx warning on
- AdBlue/DEF level or quality warning
- Possible no-start countdown after ignore period
- Failed emissions inspection (NOx)
How to diagnose it
- Review freeze-frame data and graph the bank 2 heater sense signal in live data to identify when it becomes implausible.
- Inspect the bank 2 sensor mounting and connector for looseness, corrosion, or damaged terminals that could distort the sense signal.
- Check the sense-circuit wiring for chafing, opens, shorts, or intermittent contact while monitoring the signal.
- Compare the bank 2 heater sense behavior with heater commands and sensor warm-up, using the manufacturer's specification.
- If mounting, wiring, and connections pass, test the bank 2 NOx sensor heater and internal sense circuit for drift or failure.
Common fixes
- Secure a loose bank 2 NOx sensor or correct a mounting problem affecting its signal.
- Repair intermittent or damaged wiring in the bank 2 heater sense circuit.
- Clean or repair poor connections at the bank 2 sensor connector.
- Replace the bank 2 NOx sensor if its heater sense signal remains outside specification.
Can I keep driving?
A short drive may be possible if the vehicle runs normally, but have the fault checked soon and avoid ignoring DEF or NOx warnings. Implausible heater feedback can delay accurate emissions readings and may lead to a no-start countdown on vehicles that use one.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.