Powertrain Definition only Lights the check engine lamp

P289D: Cylinder 4 Ion Current Sense Circuit Range/Performance

Standardized SAE J2012 code · P28xx codes

What does P289D mean?

The ion current signal from cylinder 4 is outside the expected range for combustion conditions. Combustion quality cannot be assessed reliably.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

Common causes

  • High Spark plug aged - electrode shape changed
  • Medium Ion sense circuit gain drift
  • Low Sensor element aged beyond calibration window

Likelihood is a general estimate across vehicles; your make and model may differ.

Add your car to see reports of P289D on the same make and model first.

P289D in the community

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