The P0350: Ignition Coil Primary/Secondary Circuit Malfunction code indicates that the engine control module (ECM) has detected a problem in the ignition coil circuit. This circuit controls the flow of electricity to the ignition coil, which is responsible for creating the spark necessary for combustion in the engine. A malfunction in this circuit can cause misfires, poor engine performance, or stalling.
P0350 – Quick Overview
Meaning | P0350: Ignition Coil Primary/Secondary Circuit Malfunction |
Is it serious? | Yes, this code is serious as it can cause engine misfires, stalling, and poor performance, which could lead to further engine damage. |
Possible causes | – Faulty ignition coil – Wiring or connection faults – Circuit issues |
How to diagnose? | – Test ignition coil functionality – Inspect and repair wiring – Replace ignition coil if necessary |
P0350 Meaning
The P0350: Ignition Coil Primary/Secondary Circuit Malfunction code means that the ECM has detected an issue with the primary or secondary circuits of one or more ignition coils. The ignition coils are responsible for generating the spark that ignites the air-fuel mixture in the engine cylinders. If these circuits fail, the engine may experience misfires, loss of power, rough idling, or stalling.
Step-by-step diagnostic guide
Follow these steps to diagnose and resolve the P0350 code by addressing potential causes one by one.
Action | Description | Tools Needed |
---|---|---|
Check for Other Codes | Use an OBD-II scanner to check for other related codes that may provide further insights into the problem. | OBD-II Scanner |
Inspect the Ignition Coil | Visually inspect the ignition coil for signs of damage, corrosion, or wear. Ensure that the coil is properly mounted and securely connected. | Flashlight, Safety Gloves |
Test Ignition Coil Functionality | Use a multimeter to test the ignition coil’s primary and secondary circuits. Compare the resistance readings to the manufacturer’s specifications. | Multimeter, Manufacturer’s Specifications |
Inspect and Repair Wiring | Inspect the wiring and connectors leading to the ignition coil for any signs of damage, corrosion, or poor connections. Repair or replace faulty wiring as necessary. | Flashlight, Wiring Repair Kit |
Replace the Ignition Coil if Necessary | If the ignition coil is faulty, replace it with a new one to restore proper engine performance and prevent further misfires. | Replacement Ignition Coil, Safety Gloves |
Clear the Code and Test Drive | After completing repairs, clear the P0350 code using an OBD-II scanner. Test drive the vehicle to ensure the issue is resolved. | OBD-II Scanner, Vehicle Owner’s Manual |
Recheck for Codes | After the test drive, re-scan the vehicle to ensure the P0350 code has not returned. If the code reappears, further diagnosis may be required. | OBD-II Scanner |
This diagnostic guide will help you resolve the P0350 code, ensuring that the ignition coil circuit is functioning correctly, and the engine is performing optimally without misfires or performance issues.
Free PDF: How to choose OBD2 scanner

I’ve made you a free PDF to choose the OBD2 scanner in 5 minutes.
✅ Which OBD2 scanner is best?
✅ Which type should you get (DIY, Pro, Hobby)
✅ What is the best scanner for the exact brand/feature (e.g best for BMW)
✅ How to get a Bi-Directional tool for as cheap as $40
✅ Discount coupons for scanners
PDF is 100% free and it is designed to help you pick a scanner in less than a few minutes! Not a boring 50-page guide.
Just tell me where to send it.

Hi, I am Juraj “Yuri” Lukacko. I got frustrated by unhelpful and scammy mechanics, so I decided to learn everything about car diagnostics myself. I test dozens of new car diagnostic tools every month along with learning new strategies to fix and customize cars. About Juraj Lukacko (Yuri)