NOx Sensor Heater Sense Circuit Intermittent (Bank 1)
Common Symptoms
- Check engine light illuminated
- NOx sensor heater diagnostic trouble codes present
- Intermittent loss of NOx sensor readings
- Reduced engine power or derate in some diesel applications
- Increased diesel exhaust fluid consumption
- Failed emissions test
Most Likely Root Causes
- Intermittent wiring or connector issues at NOx sensor heater circuit
- Corroded or loose NOx sensor electrical connector
- Damaged or chafed wiring harness near exhaust system
- Faulty NOx sensor heater element
- Water intrusion in sensor connector or wiring
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Component Location
NOx sensor is typically mounted in the exhaust stream downstream of the diesel particulate filter or SCR catalyst on diesel engines.
Manufacturer Notes
This intermittent heater circuit code is common on diesel aftertreatment systems and often relates to connector corrosion from exhaust moisture exposure.
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