Ignition Coil D Circuit Malfunction
The engine computer has detected a problem in the ignition coil circuit for cylinder D. This can stop that cylinder from firing properly and cause misfires, rough running, or hard starting.
You may be able to drive short distances, but the engine may run poorly and can damage the catalytic converter if it misfires heavily. Do not keep driving if the check engine light is flashing or the engine is shaking badly.
P0354 means the engine control module has detected an electrical fault in the primary or secondary ignition coil circuit for coil D. This is usually on a coil-on-plug system and may involve the coil itself, wiring, connector, power supply, ground, or the driver circuit in the ECM/PCM. The fault can cause one cylinder to lose spark, leading to a misfire and poor engine performance.
It usually refers to the fourth ignition coil or the coil assigned to a specific cylinder, depending on the vehicle design. Check the service information for the exact cylinder mapping.
Yes. A worn or damaged spark plug can overload the coil or contribute to misfires, but the code usually points first to the coil circuit, wiring, or coil itself.
No. The code will come back if the electrical fault is still present.
Yes, it can be serious if the engine is misfiring. Continued driving can damage the catalytic converter and make the vehicle run poorly.