NOx Sensor Heater Circuit High (Bank 2)
What does P2217 mean?
The P2217 code means the vehicle's onboard diagnostic system has detected: NOx Sensor Heater Circuit High (Bank 2). This is a moderate severity code.
Common Symptoms
- Check Engine Light on
- Possible burning smell from wiring
- Failed emissions test
- SCR system warning
- Potential limp mode
Probable Causes (Ranked by Likelihood)
- Short to voltage in the Bank 2 heater circuit wiring Very High
- Internally shorted Bank 2 NOx sensor heater element High
- Water intrusion causing a short in the Bank 2 connector Moderate
- Melted wiring near exhaust components on Bank 2 Moderate
- ECM heater driver outputting excessive current on Bank 2 Low
Step-by-Step Diagnostic Procedure
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Measure Bank 2 heater circuit current draw and compare to spec
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Inspect wiring for shorts to power near exhaust heat sources
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Check the Bank 2 sensor connector for water intrusion or melted pins
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Measure heater element resistance -- very low reading indicates internal short
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Replace the Bank 2 NOx sensor if heater element is shorted
Frequently Asked Questions
What does high circuit mean for the Bank 2 heater?
It means excessive current is flowing through the Bank 2 NOx sensor heater circuit, usually from a short to voltage in the wiring or an internally shorted heater element with abnormally low resistance.
Can excessive heater current blow a fuse?
Yes, if the heater circuit is shorted, the excess current can blow the heater fuse. If you find a blown fuse, check for shorts before replacing it.
How do I protect the wiring from exhaust heat?
Ensure all heat shields and wire loom protection are in place. Damaged or missing heat shielding should be replaced to prevent the wiring harness from being exposed to excessive exhaust temperatures.