P2898 indicates a problem in the ion-current sensing circuit for cylinder 3. The engine controller uses this circuit to monitor combustion by measuring electrical current through the spark plug after ignition, so a fault means the signal is missing, erratic, or outside the expected range for that cylinder.
The coil or integrated ion-sense component for cylinder 3 is the most common source. Internal damage can distort or interrupt the ion-current signal sent back to the PCM.
Open, shorted, corroded, or loose terminals in the harness between the coil/module and the PCM can produce this code. Heat, oil contamination, and chafing are typical culprits.
A worn, fouled, or damaged spark plug can alter ion current enough to set a circuit-related code, even before a conventional misfire code appears.
On systems that use a separate sensing module, that module may fail to process or return the cylinder 3 signal correctly.
PCM failure is genuinely rare for this code. It should only be considered after the coil, wiring, spark plug, and any sensing module have been ruled out.
No. P2898 is a circuit fault for the ion-current sensing system. It may or may not cause an actual misfire, and it can set even when combustion appears normal if the sensing signal is bad.
Yes, a worn or fouled spark plug can change ion current enough to trigger this code, so the plug and its boot should be inspected before replacing more expensive parts.
Usually no. PCM failure is uncommon for this code. Most cases are caused by the ignition coil/ion-sense component, wiring, or spark plug. Only consider the PCM after those are fully ruled out.
Short trips are generally okay if the engine runs smoothly, but a real misfire or incomplete combustion can overheat the catalytic converter. Have it diagnosed promptly.