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P codepowertrainMedium severity

P2210NOx Sensor Heater Sense Circuit Low (Bank 1)

The Bank 1 NOx sensor heater sense circuit is stuck at a low voltage, usually from a short to ground or an open feedback wire.

Definition

The control module reads a heater sense (feedback) circuit to verify the Bank 1 NOx sensor heater is drawing current and regulating element temperature. P2210 sets when that feedback voltage stays below the plausible minimum, pointing to a short to ground, an open sense wire, or a failed feedback stage inside the sensor's integrated module. With heater operation unverified, the module discards NOx data, illuminates the MIL, and leaves the NOx and SCR readiness monitors incomplete, which fails an emissions inspection and can degrade DEF dosing control on diesels.

Common causes

  • Heater sense wire shorted to ground
  • Open feedback circuit from broken wiring or a backed-out terminal
  • Failed NOx sensor internal feedback circuitry
  • Connector corrosion or water intrusion
  • Harness chafed against the frame or exhaust shielding

Common misdiagnoses

  • SCR catalyst
  • DEF doser/injector
  • Vehicle battery or grounds replaced wholesale
  • Oxygen sensor heater circuit

Troubleshooting steps

  1. 1.Confirm the code and check companions

    If heater control codes also set, diagnose shared supply/ground first; an isolated P2210 points specifically at the sense line or sensor.

  2. 2.Test the sense circuit for a short to ground

    With the sensor and module disconnected, verify no continuity between the sense wire and chassis ground.

  3. 3.Check sense circuit continuity

    Measure end-to-end resistance of the feedback wire; more than about 1 ohm or an open reading indicates a harness repair is needed.

  4. 4.Inspect connectors at both ends

    Look for spread female terminals, corrosion, and moisture in the sensor module connector, a common failure point on underbody-mounted sensors.

  5. 5.Replace the NOx sensor if the circuit is intact

    A good harness with a dead feedback signal means the sensor's internal monitoring circuit has failed; fit an OE sensor and verify monitor readiness.

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