This code indicates the powertrain control module has detected an issue with the secondary side of an ignition coil, which is the high-voltage circuit responsible for firing the spark plug. It typically means the coil is failing to produce or deliver the necessary spark energy to the cylinder.
The internal secondary winding of the coil has shorted, opened, or suffered insulation breakdown, preventing proper high-voltage output. This is the most common point of failure for this code.
A spark plug with an excessive gap or heavy carbon buildup increases electrical resistance, which can cause the secondary circuit to fail to fire correctly.
Torn insulation, moisture, or carbon tracking allows the high voltage to arc to the engine block or cylinder head before reaching the spark plug.
Corroded, loose, or chafed wiring at the ignition coil connector can disrupt the signals the PCM uses to monitor the secondary circuit.
A rare internal failure in the engine computer's monitoring or driver circuit, which should only be considered after all mechanical and wiring issues are definitively ruled out.
It is only safe for very short distances to reach a repair location. Driving with an ignition secondary circuit failure can cause unburned fuel to enter the catalytic converter, leading to overheating and expensive converter damage.
Yes. A worn or fouled spark plug increases the electrical resistance in the secondary circuit, which can prevent the coil from firing properly and trigger the code.
The code definition or freeze frame data usually points to a specific cylinder bank or position. You can also swap the coil with an adjacent cylinder to see if the misfire or code moves to the new location.
Almost never. While some may suggest a computer failure, this code is overwhelmingly caused by a failed ignition coil, a bad spark plug, or damaged wiring. The PCM should be the very last component suspected and tested.