Powertrain
Definition only
Lights the check engine lamp
P28AF: Cylinder 8 Ion Current Sense Circuit High
Standardized SAE J2012 code · P28xx codes
What does P28AF mean?
Ion current from cylinder 8 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 P28AF on the same make and model first.
P28AF in the community
Ask about P28AFNo one has posted about P28AF yet
Share your vehicle, the tool you used and what you tested — the first thread helps everyone who searches for this code.
Describe your P28AF problemRelated codes
- P2893 Cylinder 1 Ion Current Sense Circuit High
- P2897 Cylinder 2 Ion Current Sense Circuit High
- P289B Cylinder 3 Ion Current Sense Circuit High
- P289F Cylinder 4 Ion Current Sense Circuit High
- P28A3 Cylinder 5 Ion Current Sense Circuit High
- P28A7 Cylinder 6 Ion Current Sense Circuit High
- P28AB Cylinder 7 Ion Current Sense Circuit High
- P28B3 Cylinder 9 Ion Current Sense Circuit High
- P28B7 Cylinder 10 Ion Current Sense Circuit High
- P28BB Cylinder 11 Ion Current Sense Circuit High
- P28BF Cylinder 12 Ion Current Sense Circuit High