Ignition Coil G Primary/Secondary Circuit Malfunction
Code P0357 indicates a malfunction in ignition coil G's primary or secondary circuit, which prevents proper spark generation for that cylinder. This is typically caused by electrical faults in the coil-on-plug (COP) driver circuit, loose connections, or a failed coil pack.
What You Might Notice
- Check Engine Light (MIL) illumination
- Engine misfire on cylinder G
- Rough idle or hesitation during acceleration
- Reduced fuel economy
- Possible loss of power under load
Most Common Causes
- 1
Bad Ignition Coil Pack
The coil-on-plug (COP) for cylinder G has failed internally or has a broken winding, preventing proper spark voltage generation.
- 2
Loose or Corroded Connector
The connector at the ignition coil is loose, corroded, or has broken connector locks, causing poor electrical contact and circuit malfunction.
- 3
Short or Open in Driver Circuit Wiring
The wiring between the PCM and ignition coil G has a short to voltage/ground or an open circuit, disrupting the driver signal.
- 4
Faulty Powertrain Control Module
The PCM's ignition coil driver output for cylinder G is defective, preventing proper signal transmission to the coil.
How to Diagnose It
- 1
Check Bad Ignition Coil Pack — The coil-on-plug (COP) for cylinder G has failed internally or has a broken winding, preventing proper spark voltage generation.
- 2
Check Loose or Corroded Connector — The connector at the ignition coil is loose, corroded, or has broken connector locks, causing poor electrical contact and circuit malfunction.
- 3
Check Short or Open in Driver Circuit Wiring — The wiring between the PCM and ignition coil G has a short to voltage/ground or an open circuit, disrupting the driver signal.
- 4
Check Faulty Powertrain Control Module — The PCM's ignition coil driver output for cylinder G is defective, preventing proper signal transmission to the coil.
How to Fix It
- 1
Replace Ignition Coil G
Remove the faulty coil-on-plug from cylinder G and install a new OEM or quality aftermarket replacement. Ensure the connector is fully seated and secure.
- 2
Inspect and Repair Coil Connector
Check the connector at coil G for corrosion, loose pins, or broken locks. Clean contacts with electrical cleaner, repair or replace the connector, and ensure a tight connection.
- 3
Diagnose and Repair Wiring
Use a multimeter to test the driver circuit wiring between the PCM and coil G for continuity and shorts. Repair or replace damaged wiring as needed.
- 4
Test and Replace PCM if Necessary
After ruling out coil and wiring issues, have a professional test the PCM's ignition driver output with a scope. If defective, the PCM may need replacement or reprogramming.
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