Ignition Coil Primary/Secondary Circuit Malfunction
The ignition coil primary or secondary circuit has an open or short condition, preventing proper spark generation. This code indicates a critical ignition system failure that will cause severe misfires and engine damage if driven.
What You Might Notice
- Engine misfiring or multiple cylinder misfires
- Poor engine performance and hesitation
- Significant loss of power and acceleration
- Reduced fuel efficiency
- Check engine light illuminated
Most Common Causes
- 1
Defective Ignition Coil or Coil Pack
The ignition coil or coil pack has failed internally, creating an open or short circuit in the primary/secondary windings. This is the most common cause of P0350.
- 2
Damaged Primary/Secondary Wiring
The wiring harness connecting to the ignition coil is open, shorted, or corroded, preventing proper electrical signal transmission. Check for burned, chafed, or water-damaged wires.
- 3
Faulty Ignition System Relay
The relay controlling power to the ignition coil circuit has failed or contacts are burned out, cutting power to the coil.
- 4
Blown Fuses or PCM Malfunction
A blown fuse or fusible link interrupts power to the ignition system, or the PCM has failed and cannot control the coil circuit properly.
How to Diagnose It
- 1
Check Defective Ignition Coil or Coil Pack — The ignition coil or coil pack has failed internally, creating an open or short circuit in the primary/secondary windings. This is the most common cause of P0350.
- 2
Check Damaged Primary/Secondary Wiring — The wiring harness connecting to the ignition coil is open, shorted, or corroded, preventing proper electrical signal transmission. Check for burned, chafed, or water-damaged wires.
- 3
Check Faulty Ignition System Relay — The relay controlling power to the ignition coil circuit has failed or contacts are burned out, cutting power to the coil.
- 4
Check Blown Fuses or PCM Malfunction — A blown fuse or fusible link interrupts power to the ignition system, or the PCM has failed and cannot control the coil circuit properly.
How to Fix It
- 1
Replace Ignition Coil or Coil Pack
Remove the faulty ignition coil/coil pack and install a replacement. Test for proper spark generation after installation. This resolves the majority of P0350 codes.
- 2
Inspect and Repair Wiring Harness
Visually inspect the ignition coil wiring for damage, corrosion, or loose connections. Repair or replace damaged wires and ensure all connectors are clean and seated properly.
- 3
Replace Ignition System Relay
Locate the ignition relay in the fuse/relay box and test it with a multimeter. If defective, replace with an OEM equivalent relay and verify proper operation.
- 4
Check Fuses and Test PCM
Inspect the ignition system fuses and fusible links for blown conditions and replace if needed. If all electrical components test good, have the PCM tested or reprogrammed by a dealer.
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