Powertrain Definition only Lights the check engine lamp

P28AB: Cylinder 7 Ion Current Sense Circuit High

Standardized SAE J2012 code · P28xx codes

What does P28AB mean?

Ion current from cylinder 7 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 P28AB on the same make and model first.

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