Faulty ignition coil 'E' (primary or secondary winding failure); Worn or damaged spark plug or spark plug boot for that cylinder; Damaged or corroded wiring harness or connector at the coil; Open or short circuit in the coil primary circuit; Failed ignition control module or driver inside the ECM (less common); Poor ground connection for the ignition system; Aftermarket or incorrect coil installed previously

DTC codes / P03xx · Ignition system and misfire / P0355

P0355Ignition Coil 'E' Primary/Secondary Circuit

Q: What does code P0355 mean?

Ignition Coil 'E' Primary/Secondary Circuit. P0355 indicates that the engine control module (ECM) has detected a fault in the primary or secondary circuit of ignition coil 'E', which is typically the fifth coil in the firing order on a multi-coil engine. The ECM monitors the coil's electrical behavior and sets this code when the circuit does not match expected voltage or current patterns during operation.

P0355 indicates that the engine control module (ECM) has detected a fault in the primary or secondary circuit of ignition coil 'E', which is typically the fifth coil in the firing order on a multi-coil engine. The ECM monitors the coil's electrical behavior and sets this code when the circuit does not match expected voltage or current patterns during operation.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Rough idle or misfire sensation, especially when the engine is cold or under load
Reduced engine power and poor acceleration
Shaking or vibration from the engine bay
Worsened fuel economy due to incomplete combustion
In some cases, the engine may enter limp mode to protect the catalytic converter

Common causes, most likely first

Faulty ignition coil 'E' (primary or secondary winding failure)
Worn or damaged spark plug or spark plug boot for that cylinder
Damaged or corroded wiring harness or connector at the coil
Open or short circuit in the coil primary circuit
Failed ignition control module or driver inside the ECM (less common)
Poor ground connection for the ignition system
Aftermarket or incorrect coil installed previously

How to diagnose and fix it

Perform a visual inspection of coil 'E', its connector, and wiring for damage or corrosion
Swap coil 'E' with a known-good coil from another cylinder and see if the misfire follows the coil
Test the coil's primary and secondary resistance with a multimeter and compare to specifications
Check for spark at the affected cylinder using a spark tester
Inspect the spark plug and replace if worn or fouled
Test the wiring between the coil and ECM for continuity and shorts
If all else checks out, diagnose the ECM driver circuit or replace the ECM as a last resort

Coil 'E' circuit faults often misdiagnosed

A bad spark plug or boot can cause a P0355 code even if the coil itself is good, so always inspect the secondary ignition components first.
The code refers to coil 'E' by its position in the firing order, not necessarily cylinder number 5, so consult the specific vehicle's coil labeling before swapping parts.
Intermittent wiring faults can set P0355 without a constant misfire; wiggle-test the harness while the engine is running to catch them.
A failing ECM driver for coil 'E' is rare but possible, especially if the coil and wiring test good and the code persists after swapping coils.
P0355 can be triggered by a poor ground connection at the engine block, which affects all coils but may set a code for only one.

Can I keep driving with P0355?

You can drive cautiously to a repair shop if the engine runs smoothly, but avoid heavy acceleration or towing. If the check engine light flashes or the engine misfires severely, stop driving to prevent catalytic converter damage.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.