P2222: NOx Sensor Heater Sense Circuit Range/Performance Bank 2
What to do
Ask for the battery and charging system to be checked before this sensor is condemned, particularly if similar faults are stored for other heated sensors. Low supply voltage produces heater performance faults on perfectly healthy sensors, and it is a far cheaper repair than the part it gets mistaken for.
What this code means
The bank 2 heater sense circuit reports a valid reading that does not make sense — usually the heater not reaching or not holding the commanded temperature.
The cheap check named at P2209 comes first and matters most: heater output falls with the square of supply voltage, so a weak battery or a marginal charging system reduces heating power sharply while every circuit still tests continuous — and it does so on every heated sensor at once.
Likely causes
Start here
- Low system voltage · moderate
- Faulty NOx sensor · moderate
- High resistance in heater wiring · moderate
Less common
- Corroded or loose connector · easy
- Faulty alternator · moderate
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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