Common Symptoms
- Check Engine Light or Malfunction Indicator Lamp illuminated
- Reduced engine power or derate condition
- Poor fuel economy
- Increased diesel exhaust fluid (DEF) consumption
- Exhaust aftertreatment warning messages on instrument cluster
Most Likely Root Causes
- Failed or degraded NOx sensor on bank 2
- Contaminated NOx sensor from coolant, oil, or fuel additives
- Damaged wiring harness or connectors to NOx sensor
- Exhaust leaks upstream of NOx sensor affecting readings
- DEF system malfunction causing abnormal NOx readings
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Component Location
NOx sensor bank 2 is typically located in the exhaust system downstream of the SCR catalyst on the opposite bank from sensor bank 1.
Manufacturer Notes
NOx sensors on diesel aftertreatment systems are sensitive to contamination and require proper DEF fluid quality for accurate operation.
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