Ignition Coil Primary/Secondary Circuit Malfunction
The P0350 code means the vehicle's onboard diagnostic system has detected: Ignition Coil Primary/Secondary Circuit Malfunction. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- moderate
- Estimated cost
- $100 - $400 (parts and labor)
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What Are the Symptoms of P0350?
- Engine misfires on one or more cylinders
- Rough idle and vibration
- Check Engine Light illuminated
- Reduced power and acceleration
- Poor fuel economy
What Causes P0350? (Most Likely First)
- Faulty ignition coil Very High
- Damaged coil connector or wiring High
- Worn or fouled spark plug causing coil overload High
- PCM ignition coil driver circuit failure Moderate
- Poor engine ground affecting coil circuit Low
Can I Still Drive with P0350?
Short distances only. P0350 is rated moderate severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.
Frequently Asked Questions
Can I drive with code P0350?
You can drive short distances. The engine will misfire and run rough. Prolonged driving with a misfiring cylinder can damage the catalytic converter.
Should I replace all ignition coils at once?
It is not strictly necessary, but if one coil has failed and the others are the same age with high mileage, replacing them as a set can prevent future failures and save on repeat labor.
Can a bad spark plug kill an ignition coil?
Yes. A worn or gapped-too-wide spark plug forces the coil to produce higher voltage, which can overheat and burn out the coil prematurely. Always replace spark plugs at recommended intervals.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose P0350?
-
Check for companion misfire codes (P0301-P0312) to identify the affected cylinder
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Measure ignition coil primary resistance -- should be 0.4-2.0 ohms; secondary resistance should be 6,000-15,000 ohms
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Swap the suspect coil with a known-good coil from another cylinder -- if the misfire follows, the coil is bad
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Inspect the coil connector for corrosion, melted plastic, or damaged pins
-
Check the spark plug condition -- a worn or fouled plug can cause premature coil failure
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Which Vehicles Commonly Get P0350?
- 2007-2017 Toyota Camry
- 2008-2018 Honda Accord
- 2005-2015 Ford F-150
- 2010-2020 Chevrolet Silverado
- 2009-2019 Nissan Altima
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