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2003 INFINITI FX45
4.5L V8•AWD•AUTOMATIC•gas
9 active safety recalls on this vehicle — view recalls
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Repairs0Labor475Torque2094Fluid7DTC1778Battery1Maintenance0Recalls9
P2209moderate severityPowertrain

NOx Sensor Heater Sense Circuit Intermittent

on 2003 Infiniti FX45 4.5L V8 · AWD

What this code means

The PCM detects an intermittent fault in the NOx sensor heater sensing circuit. This can affect emissions monitoring and aftertreatment performance.

Symptoms

  • Check engine light on
  • Intermittent emissions warning
  • Reduced aftertreatment efficiency

Common causes

  • Loose or corroded NOx sensor connector
  • Damaged NOx sensor heater wiring
  • Faulty NOx sensor
  • Intermittent ground or power fault

Diagnostic steps

  1. Scan for related NOx codes
  2. Inspect sensor connector and wiring
  3. Wiggle-test harness while monitoring data
  4. Replace NOx sensor if wiring checks out
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