P0356 Code Meaning and Next Steps

First checks take 10 to 20 minutes for the first checks. No special tools are usually needed for the first checks.

Can you keep driving?

Stop driving if any of these apply

!The engine starts running much worse, stalls, or the warning light flashes.
!The vehicle begins to lose power sharply or misfire badly while the code is active.

If the light is steady and the vehicle still drives normally: Maybe, but only for a very short distance if the engine still runs smoothly.

What to check first

Step-by-step checks

1
Safety first
If the check-engine light is flashing or the engine is shaking badly, stop driving before you inspect anything else
2
Free - no tools
Inspect the coil 6 connector, harness, and nearby wiring for damage, loose fit, or corrosion
3
Basic tool needed
Check whether the engine also has a misfire code that points toward the same cylinder or coil path
4
Basic tool needed
If the vehicle has coil-on-plug ignition, look for oil intrusion, cracked boots, or moisture in the coil well
5
Basic tool needed
If scan data is available, compare misfire counts before and after a swap test

If the code returns

-If the fault follows a swap test, the coil itself moves higher on the list.
-If the code returns after connector repair, revisit the control circuit and harness continuity.
-If the misfire stays after coil checks, plug, injector, or compression testing becomes more important.

Background

What this code means

P0356 is a generic OBD-II ignition coil circuit code.

It does not always mean the coil itself is dead. Power, ground, wiring, or a driver-side fault can trigger the same warning.

A rough idle, misfire, or flashing light can appear when the coil circuit is not working correctly.

Diagnosis

Common causes

Most common

Failed ignition coil

The coil may be weak, open, or failing under load.

Common

Connector or wiring issue

A loose or damaged connection can interrupt the circuit.

Common

Driver circuit fault

The ECU output may not be commanding the coil normally.

Possible

Spark plug or plug-well issue

A plug gap, oil intrusion, or moisture problem can overload the coil.

Avoid these mistakes

What not to do

xDo not replace sensors first if the wiring, connector, or mechanical timing side has not been checked.
xDo not ignore drivability changes just because the code sounds like a sensor or circuit problem.

Parts

Parts that may need replacing

PartTypical costNotes

Ignition coil$30-$180Relevant when the coil tests bad or the fault follows a swap.

Spark plug$10-$40Often worth checking at the same time if the plug is worn or fouled.

Connector pigtail repair$15-$90Useful if the plug or pins are damaged.

Related OBD codes

P0300

P0300 usually means the engine is detecting random or multiple-cylinder misfires.

P0350

P0350 usually means ignition coil 0 circuit malfunction.

P0357

P0357 usually means ignition coil 7 circuit malfunction.

Source notes

Generic OBD-II (SAE J1979 / ISO 15031-5). P0356 was expanded around common ignition coil circuit faults, including coil failure, connector issues, and harness damage.

This guide is written as a generic multi-make reference, so bulletin history, sensor locations, and repair order can still change by manufacturer and engine family.

This is generic OBD-II guidance and should not override vehicle-specific service information. Exact diagnosis and repair steps vary by make, engine family, and model year.

Last reviewed: 2026-04-10

Reference: Open reference

P0356 - P0356 Usually Means Ignition Coil 6 Circuit Malfunction