Faulty ignition coil 'G' (internal winding failure or short); Damaged or corroded electrical connector at the coil; Open or shorted wiring in the coil's primary or secondary circuit; Failed spark plug or excessive spark plug gap causing coil overload; PCM driver circuit failure for coil 'G'; Poor ground connection for the ignition coil circuit; Aftermarket or incorrect coil installed that does not meet specifications

DTC codes / P03xx · Ignition system and misfire / P0357

P0357Ignition Coil 'G' Primary/Secondary Circuit

Q: What does code P0357 mean?

Ignition Coil 'G' Primary/Secondary Circuit. P0357 indicates that the powertrain control module (PCM) has detected a fault in the primary or secondary circuit of ignition coil 'G', which is the seventh coil in the engine's firing order or a specific coil designated by the manufacturer. The PCM monitors the coil's electrical circuit and sets this code when the current or voltage falls outside the expected range during operation.

P0357 indicates that the powertrain control module (PCM) has detected a fault in the primary or secondary circuit of ignition coil 'G', which is the seventh coil in the engine's firing order or a specific coil designated by the manufacturer. The PCM monitors the coil's electrical circuit and sets this code when the current or voltage falls outside the expected range 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
Noticeable loss of power or hesitation during acceleration
Shaking or vibration from the engine bay that may feel like a misfire
Reduced fuel economy due to incomplete combustion in the affected cylinder
In some cases, the engine may enter limp mode or flash the check engine light if the misfire is severe

Common causes, most likely first

Faulty ignition coil 'G' (internal winding failure or short)
Damaged or corroded electrical connector at the coil
Open or shorted wiring in the coil's primary or secondary circuit
Failed spark plug or excessive spark plug gap causing coil overload
PCM driver circuit failure for coil 'G'
Poor ground connection for the ignition coil circuit
Aftermarket or incorrect coil installed that does not meet specifications

How to diagnose and fix it

Perform a visual inspection of coil 'G', its connector, and wiring for damage or corrosion
Swap coil 'G' with a known-good coil from another cylinder and see if the code follows the coil
Check the spark plug condition and gap for the affected cylinder, replacing if worn or fouled
Use a multimeter to test the coil's primary and secondary resistance against manufacturer specifications
Inspect the wiring harness for opens, shorts, or high resistance between the coil and PCM
Test the PCM driver circuit with a noid light or oscilloscope to confirm proper signal
Replace the faulty ignition coil or repair wiring as needed, then clear the code and verify repair

Coil 'G' circuit faults often misdiagnosed

A P0357 can be set by a faulty spark plug or excessive gap that overloads the coil, so always inspect plugs before replacing the coil.
The code does not always mean the coil itself is bad; wiring harness chafing or a poor ground can cause the same symptom.
Swapping coils between cylinders is a quick diagnostic step, but be aware that some engines use different coil types for different cylinders.
Intermittent faults may only appear when the engine is hot or under specific load conditions, so a wiggle test of the harness while running can reveal the issue.
A failed PCM driver is rare but possible; confirm all other causes before condemning the PCM.

Can I keep driving with P0357?

It is generally safe to drive with a P0357 code if the engine runs smoothly, but avoid heavy acceleration or towing until repaired. 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.