Common Symptoms
- Check engine light illuminated
- Reduced engine power or derate condition
- Poor fuel economy
- Increased exhaust emissions
- Regeneration cycle frequency changes
- NOx sensor heater malfunction warning
Most Likely Root Causes
- Failed NOx sensor heater element
- Damaged wiring or connectors to NOx sensor
- Short to voltage in NOx sensor heater circuit
- Faulty engine control module
- Corroded or moisture-damaged sensor connector
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Component Location
NOx sensor is typically located in the exhaust system downstream of the diesel particulate filter or SCR catalyst on Bank 1.
Manufacturer Notes
Diesel engines with selective catalytic reduction systems require proper NOx sensor heater operation for accurate emission control and regeneration management.
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