P2323 indicates a fault detected in the high-voltage secondary circuit of ignition coil H. The engine computer monitors each coil’s output and sets this code when it sees an open, short, or weak condition on the secondary side, which can cause misfires and increased emissions.
The coil’s internal secondary winding can break down, causing weak or no spark. This is the single most common reason for a coil-specific secondary circuit code.
Cracked boots, carbon tracking, worn spark plugs, or chafed high-tension wires can leak or interrupt high voltage before it reaches the cylinder.
The high-voltage path from the coil to the plug can open, short to ground, or short to another circuit, producing the same fault.
Oil, coolant, or water in the spark plug tube or coil well can create a conductive path that disturbs the secondary circuit.
The PCM controls the coil’s primary side, so a driver failure is possible but very uncommon for a secondary-circuit code; it should be considered only after the coil, plug, boot, and wiring are ruled out.
It refers to the high-voltage side of the ignition coil that delivers spark to the plug, not the low-voltage primary side controlled by the PCM.
It is best to avoid driving far; a misfiring cylinder can overheat the catalytic converter and cause more expensive damage.
Yes. A worn, cracked, or fouled plug can alter secondary circuit resistance and trigger this code, so plugs and boots should be inspected before replacing the coil.
Usually no. PCM failure is a rare cause of a secondary-circuit code; the coil, boot, plug, and wiring are far more likely culprits and should be thoroughly tested first.