Cylinder 4 Ion Current Sense Circuit High
Ion current from cylinder 4 is above the expected window. Cross-coupled signal, biased reference, or sensor fault.
Affected components
- Spark plug cyl 4
- Ignition coil cyl 4
- Ion sense module
Common causes
- High likelihood: Inductive cross-coupling from ignition coil primary
- Medium likelihood: Sense reference voltage biased
- Low likelihood: Connector pins corroded - high contact resistance
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.