Powertrain Definition only Lights the check engine lamp

P289F: Cylinder 4 Ion Current Sense Circuit High

Standardized SAE J2012 code · P28xx codes

What does P289F mean?

Ion current from cylinder 4 is above the expected window. Cross-coupled signal, biased reference, or sensor fault.

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

Common causes

  • High Inductive cross-coupling from ignition coil primary
  • Medium Sense reference voltage biased
  • Low Connector pins corroded - high contact resistance

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

Add your car to see reports of P289F on the same make and model first.

P289F in the community

Ask about P289F

No one has posted about P289F yet

Share your vehicle, the tool you used and what you tested — the first thread helps everyone who searches for this code.

Describe your P289F problem