Powertrain Definition only Lights the check engine lamp

P28BA: Cylinder 11 Ion Current Sense Circuit Low

Standardized SAE J2012 code · P28xx codes

What does P28BA mean?

Ion current from cylinder 11 is below the expected window. Spark plug fouled, signal wire shorted to ground, or sensing path interrupted.

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

Common causes

  • High Spark plug fouled with carbon or oil
  • Medium Sense wire shorted to ground
  • 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 P28BA on the same make and model first.

P28BA in the community

Ask about P28BA

No one has posted about P28BA yet

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

Describe your P28BA problem