What it means
The bank 1 NOx sensor heater control circuit signal is above the expected range. The code does not by itself identify the heater, wiring, or control module as the cause.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The control module monitors the bank 1 NOx sensor heater control circuit to check that heater operation stays within its expected electrical range. P2207 sets when the circuit signal is higher than expected; the code alone does not prove that the sensor or module has failed.
Common causes
Most likely first.
- Sensor drift due to ageing
- Sensor contaminated with soot or condensate
- Sensor element aged beyond calibration window
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
- Check freeze-frame data and related codes for clues about when the bank 1 heater signal rises above range.
- Locate the bank 1 NOx sensor and inspect its connector and harness for loose contacts, corrosion, heat damage, or a wire contacting a power feed.
- Use the wiring diagram to check the heater circuit fuse, supply, ground, and connector condition.
- Test the bank 1 heater circuit for an open, short to supply, or other wiring fault, and compare heater readings with the manufacturer's specification.
- If circuit checks pass, compare the commanded heater operation and feedback on a scan tool, then test the module output using the manufacturer's procedure.
Common fixes
- Clean and secure a loose or corroded bank 1 sensor connector.
- Repair wiring that is shorted to a power feed or otherwise damaged.
- Replace a failed fuse or repair its supply connection after tracing the fault.
- Replace the bank 1 NOx sensor if its heater circuit fails specified tests.
- Repair the control module only if testing confirms its output is out of range.
Can I keep driving?
Driving may be possible, but incorrect heater control can leave NOx readings or emissions control unreliable and may cause an inspection failure. If a DEF warning or start countdown is displayed, have the fault addressed promptly.
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.