NOx Sensor Heater Sense Circuit High Bank 2
The P2224 code means the vehicle's onboard diagnostic system has detected: NOx Sensor Heater Sense Circuit High Bank 2. This is a moderate severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- moderate
- Estimated cost
- $100 - $600 (wiring or connector at the low end; actuator/valve replacement at the high end)
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Common Symptoms
- Check Engine Light on
- Drivability may be normal - many circuit faults show no symptom the driver notices
- The affected system may fall back to a default strategy, costing power or economy
- Related values implausible or frozen on a scan tool
Probable Causes (Ranked by Likelihood)
- Fault in the NOx Sensor Heater Sense Circuit High circuit: a fault in this circuit High
- Damaged wiring, a chafed harness, or a corroded connector at the NOx Sensor Heater Sense Circuit High High
- Failed NOx Sensor Heater Sense Circuit High Moderate
- Control module input/driver fault (rule this out last - it is the least common) Low
Frequently Asked Questions
What does P2224 mean?
P2224 is a generic OBD-II code defined by SAE J2012 as "NOx Sensor Heater Sense Circuit High Bank 2". It means the control module detected a fault in this circuit
Can I keep driving with P2224?
Yes for normal use, but get it diagnosed - the system is running on a fallback strategy and a small wiring fault left alone tends to become a bigger one.
Does P2224 mean the same thing on every car?
Yes. P2224 is in the generic (SAE J2012) range, so the definition is standardized across manufacturers. The specific component location and repair procedure still vary by vehicle - check your service information.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
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Read the code and freeze-frame data, then watch the NOx Sensor Heater Sense Circuit High live on a scan tool.
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Inspect the connector and harness at the NOx Sensor Heater Sense Circuit High before replacing anything - wiring and corrosion cause most of these.
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Back-probe the circuit and compare signal, ground, and reference voltage against the service-manual values.
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Wiggle-test the harness while watching the live value if the fault is intermittent.
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Clear the code and confirm with a road test that covers the conditions in the freeze frame.
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Commonly Affected Vehicles
- All OBD-II vehicles - this is a generic (SAE J2012) code with the same meaning across makes
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