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P codepowertrainMedium severity

P2217NOx Sensor Circuit Intermittent (Bank 2)

The Bank 2 NOx sensor signal is dropping in and out intermittently, usually from a loose connection or chafed wiring.

Definition

The control module watches the Bank 2 NOx sensor signal for continuity and stability; P2217 sets when the signal or the sensor's CAN reporting cuts in and out erratically rather than failing outright. Intermittent data forces the module to discard NOx readings, so SCR dosing runs on fallback values, the MIL illuminates (sometimes intermittently), and the NOx monitors may never complete for an emissions test. Because the fault comes and goes, wiring and connector problems are far more likely than a cleanly failed sensor.

Common causes

  • Loose, corroded, or spread terminals in the sensor connector
  • Chafed harness making intermittent contact with ground
  • Water intrusion causing intermittent shorts as moisture moves
  • Failing NOx sensor with a temperature-dependent internal fault
  • Poor CAN bus connection at a splice or junction
  • Damaged sensor module mounting allowing vibration stress on wiring

Common misdiagnoses

  • NOx sensor replaced when the connector or harness is the fault
  • SCR catalyst
  • DEF dosing components
  • Battery/charging system

Troubleshooting steps

  1. 1.Capture the fault with live data

    Graph Bank 2 NOx ppm and sensor status while wiggle-testing the harness and connector; a dropout during manipulation localizes the fault.

  2. 2.Inspect and pin-drag test the connector

    Check each terminal for proper tension with a matching test pin; replace terminals or the pigtail if any are loose or corroded.

  3. 3.Examine the harness along its full route

    Look for chafe points at the frame, heat shields, and clip locations where insulation may be worn through intermittently.

  4. 4.Check for moisture entry

    Open the sensor module connector and inspect for water staining or green corrosion; reseal or replace as needed.

  5. 5.Road test through heat cycles

    If wiring is verified and the dropout follows engine temperature rather than movement, replace the NOx sensor for an internal intermittent fault.

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