P2890 — Cylinder 1 Ion Current Sense Circuit
The ECM cannot read a valid ion current signal from cylinder 1. Ion current sensing relies on the spark plug acting as an electrode after combustion.
General code reference. Confirm the definition and diagnostic procedure for your vehicle's year, model and engine. A stored code alone does not identify a failed part.
Affected components
- Spark plug cyl 1
- Ignition coil cyl 1
- Ion sense module
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Ion sense module failed
- Wiring or connector fault
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Related codes
Sources
Check each reference's vehicle and model-year scope. General background links do not establish which fault is most likely on your vehicle.
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.