NOx Sensor Heater Circuit Low (Bank 2)
What does P2216 mean?
The P2216 code means the vehicle's onboard diagnostic system has detected: NOx Sensor Heater Circuit Low (Bank 2). This is a moderate severity code.
Common Symptoms
- Check Engine Light on
- Extended Bank 2 sensor warm-up
- Cold start emissions issues
- Possible reduced power mode
- Failed emissions test
Probable Causes (Ranked by Likelihood)
- Open circuit in the Bank 2 NOx sensor heater wiring Very High
- Failed heater element inside the Bank 2 NOx sensor High
- Corroded Bank 2 heater circuit connector Moderate
- Poor ground for the Bank 2 heater circuit Moderate
- ECM heater control driver failure for Bank 2 Low
Step-by-Step Diagnostic Procedure
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Measure voltage at the Bank 2 NOx sensor heater connector with key on
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Check the heater ground circuit for continuity
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Measure heater element resistance -- open reading means failed heater
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Inspect connectors for corrosion or backed-out pins
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Replace the Bank 2 NOx sensor if the internal heater has failed
Frequently Asked Questions
What causes low current in the Bank 2 heater circuit?
Low current is typically caused by an open circuit, such as a broken wire, failed heater element, or corroded connector that prevents current from flowing through the heater.
Can I test the heater element without removing the sensor?
Yes, you can measure resistance at the sensor connector with the sensor still installed. Disconnect the connector and measure across the heater pins with an ohmmeter.
Is the Bank 2 NOx sensor the same part as Bank 1?
On some vehicles they are identical parts, while on others they have different part numbers due to wiring length or connector differences. Always verify the part number for your specific application.