P0359 Ignition Coil I Primary/Secondary Circuit Malfunction

P0359 points to an ignition coil I primary or secondary circuit malfunction. The controller has detected an electrical or feedback problem in the coil I circuit.

Code details

Generic OBD-II · P0

System: Ignition / Misfire
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not assume the coil letter always equals a cylinder number; use service information to map coil I before replacing parts.

Symptoms of P0359

Rough idle, shaking, or a stumble under acceleration.
A flashing check-engine light during an active misfire.
Power loss and higher fuel consumption.

Common causes of P0359

Worn spark plugs, ignition coils, or plug wires.
Fuel-delivery problems — injectors, pressure, or a lean/rich mixture.
Vacuum leaks, low compression, or a mechanical fault in that cylinder.

Useful checks before replacing parts

Compare coil I command, primary voltage, misfire counters, freeze-frame load, ignition feed, driver control, and related cylinder-specific codes.
Inspect coil I connector fit, wiring to the coil and PCM, shared power supply, ground path, spark plug condition, boot tracking, and moisture intrusion.
If possible, swap the coil with another position and verify whether the fault follows the coil or stays with the coil I circuit.

Related OBD-II codes

These nearby ignition / misfire entries can help compare wording and pin down the fault area.