NOx Sensor Heater Sense Circuit (Bank 2)
What does P2219 mean?
The P2219 code means the vehicle's onboard diagnostic system has detected: NOx Sensor Heater Sense Circuit (Bank 2). This is a moderate severity code.
Common Symptoms
- Check Engine Light on
- Failed emissions test
- Extended Bank 2 sensor warm-up
- SCR system fault indicator
- Possible limp mode on cold starts
Probable Causes (Ranked by Likelihood)
- Failed Bank 2 NOx sensor heater sense feedback circuit Very High
- Open wire in the Bank 2 heater sense circuit High
- Corroded sense circuit connector pins on Bank 2 Moderate
- Bank 2 NOx sensor module internal failure Moderate
- ECM Bank 2 feedback circuit fault Low
Step-by-Step Diagnostic Procedure
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Check for voltage on the Bank 2 heater sense feedback wire at the ECM
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Inspect sense circuit wiring from the Bank 2 NOx sensor to the ECM
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Test connector pins for corrosion or poor contact
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Verify the Bank 2 sensor module is communicating heater status
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Replace the Bank 2 NOx sensor if the internal sense circuit has failed
Frequently Asked Questions
What is the heater sense circuit on Bank 2?
The heater sense circuit is a feedback loop that allows the ECM to verify the Bank 2 NOx sensor heater is operating correctly. It confirms the heater is reaching proper temperature.
Is P2219 the same as P2209 but for Bank 2?
Yes, P2209 covers the Bank 1 heater sense circuit and P2219 covers the Bank 2 heater sense circuit. The diagnostic approach is identical.
Will a failed sense circuit prevent the heater from working?
Not necessarily. The heater may still function, but the ECM cannot verify it is working properly, which triggers the fault code and may limit SCR system operation.