Quick answer: The P0350 code indicates a circuit failure in the primary or secondary circuit of one or more ignition coils. It directly affects your engine’s ignition system, preventing proper spark generation. Immediate attention is required because unburned fuel can rapidly damage your catalytic converter and cause severe engine misfires.
If your check engine light came on alongside a sudden engine stutter or severe loss of power, reading code P0350 can feel alarming. This diagnostic code points to an electrical communication breakdown within your ignition coil circuit. Below, you will find what triggers this code, key symptoms to watch for, and practical steps to resolve the issue safely.
What Does P0350 Mean?
An ignition coil converts low battery voltage into thousands of volts needed to ignite the air-fuel mixture inside the combustion chamber. The Powertrain Control Module (PCM) constantly monitors the electrical pulse sent through the ignition coil’s primary and secondary circuits. When the PCM sends a fire signal but fails to detect the expected voltage feedback or senses an open or shorted circuit, it triggers code P0350. Unlike cylinder-specific codes that pinpoint a single cylinder, P0350 points to a general failure in the ignition coil circuit system.
Symptoms
- Illuminated or flashing check engine light
- Severe engine misfiring and rough idling
- Noticeable loss of engine power under acceleration
- Engine stalling at stoplights or while idling
- Strong odor of unburned fuel from the exhaust
- Decreased fuel economy
Possible Causes
The most common mistake when diagnosing P0350 is replacing the most expensive component first without inspecting basic wiring connections.
- Loose, corroded, or damaged ignition coil electrical connectors
- Frayed, melted, or broken wiring in the ignition harness
- Weak battery or poor engine ground connections
- Failed or shorted ignition coil
- Faulty Powertrain Control Module (PCM) or internal driver circuit
Check These Yourself Before Visiting a Mechanic
- Inspect the ignition harness wiring for visible damage, melted insulation, or rodent bites near the engine block.
- Ensure every ignition coil connector is firmly pushed in and locked into place.
- Examine battery terminals and main ground cables for heavy corrosion or loose clamping bolts.
How to Fix It
- Connect an OBD-II scanner to check if P0350 is accompanied by cylinder-specific codes (P0351 through P0358).
- Inspect all wiring, connectors, and ground contacts in the ignition system for physical wear, bent pins, or corrosion.
- Check battery voltage to confirm the electrical system provides a steady 12+ volts with the key on and engine off.
- Test the suspected ignition coil’s primary and secondary resistance using a digital multimeter against factory specifications.
- Verify power and ground signals at the ignition coil plug using a multimeter or Noid light while cranking the engine.
- Repair damaged wiring or replace faulty ignition coils; if all wiring and coils pass, test the PCM output signal.
Estimated Repair Costs (2026)
| Job | Parts ($) | Labor ($) |
|---|---|---|
| Wiring or Connector Repair | $15 – $50 | $75 – $150 |
| Ignition Coil Replacement | $40 – $120 | $50 – $100 |
| Spark Plug and Coil Pack Set | $100 – $250 | $100 – $200 |
| PCM Diagnostic and Replacement | $400 – $900 | $150 – $300 |
Note: These are 2026 estimates in US dollars. Overall costs vary depending on vehicle make, model, and local shop labor rates.
Frequently Asked Questions
Can I drive with the P0350 code?
You should avoid driving with an active P0350 code. An ignition circuit failure allows unburned fuel to pass into the exhaust system, where it can overheat and destroy the catalytic converter, resulting in far higher repair bills.
How do I clear the P0350 code?
You can clear P0350 using an OBD-II scan tool after repairing the circuit fault or replacing the failed part. Clearing the code without fixing the electrical breakdown will cause the check engine light to return immediately when the engine restarts.
Can a low battery trigger code P0350?
Yes, low system voltage or a failing alternator can lead to voltage drops in the ignition coil circuit. This fluctuation can prevent the PCM from receiving proper feedback signals, setting code P0350 even if the coils themselves are functional.