P0357 Code: Meaning, Symptoms, Causes & How to Fix it

An engine misfire could indicate a wide range of issues with your vehicle. When your powertrain control module (PCM) detects an issue with the ignition coil ‘G’, it triggers the P0357 code. This article explains the P0357 code symptoms, its causes, and how to fix it.

P0357 Code Definition

P0357 code stands for “Ignition Coil ‘G’ Primary/Secondary Circuit Malfunction.”

What Does the P0357 Code Mean?

The P0357 code indicates that your powertrain control module (PCM) detects a potential issue either in the primary or secondary circuit for ignition coil G.

P0357 Code 

The ignition system takes low voltage from the battery and converts it into high voltage to ignite the air-fuel mixture in the combustion chamber. The low-voltage side of the system is called the primary circuit.

The latest engines have a coil on plug (COP) ignition system, which places the ignition coils on top of the spark plugs to improve combustion and reduce misfires. 

If your PCM/ECM notices an open or short in the coil circuit for the number seven coil, it might register a P0357 code.

Causes of the P0357 Code

  • Short or Open in the wire between the ignition coil and PCM
  • Bad ignition coils
  • Open or shorted wiring in the ignition coil driver circuit
  • Bad connector locks
  • Bad connections at the coil
  • Faulty spark plug
  • Vacuum leaks
  • Short or open COP driver circuit
  • Faulty PCM

Symptoms of the P0357 Code

  • Engine misfiring
  • Poor engine performance
  • Poor fuel economy
  • Rough or erratic idle
  • Vehicle may enter the limp mode
  • Difficult to start the vehicle
  • Check engine light is flashing

How to diagnose the P0357 Code?

  • Use an OBD-II scanner to download all the stored codes. 
  • Use the freeze frame data to check the stored trouble codes.
  • After inspection and major repairs, clear the codes.
  • Test drive your vehicle. If the P0357 code return, then move for further inspection.
  • Perform a visual inspection of the ignition coil ‘G’ connections and wiring.
  • Inspect the coil pack of the vehicle.
  • Properly inspect the connectors for damage.
  • Inspect the spark plug for corrosion or damage.
  • Inspect the intake manifold to check the vacuum leaks.
  • Properly inspect the primary ignition coil for damaged.
  • Test the PCM if no fault has been found up until this point.

Common P0357 Code Diagnostic Mistakes

  • Replacing the needless components
  • Replacing the parts without testing them
  • Not inspecting the wires and connections before replacing the ignition coil or spark plug
  • Forgetting to plug in the distributor if applicable 
  • Clearing the PCM memory without first confirming the issue

Repair Cost of P0357 Code

To fix the P0357 code, you need one of the below-given repairs:

PCM replacement$240 to $3,000
Spark Plug replacement$60 to $260
Vacuum leak repair$70 to $380
Ignition coil replacement$160 to $220

FAQ Section

What repairs can fix the P0357 Code?

  • Replacing the damaged or corroded ignition coil wires
  • Fixing the vacuum leaks
  • Replacing the bad ignition coil
  • Replacing the bad spark plugs
  • Clean the clogged throttle body
  • Replacing the bad wiring harnesses
  • Replacing bad PCM/ECM

Can I drive with P0357 Code?

Yes, you can drive with the P0357 code but it is not recommended. This code generates different driveability problems such as poor acceleration and engine stalling. Driving with this code is very hazardous. Therefore, as you notice this code, you should contact a professional to fix it.

How do I fix my ignition coil code?

  • Replace the damaged or corroded ignition coil wires
  • Replace the fuel injector
  • Replace the fuel pump
  • Repair the vacuum leaks
  • Replace the bad ignition coils
  • Replace the bad wiring harnesses
  • Replace the bad spark plugs
  • Clean the clogged throttle body
  • Replace or reprogram the bad PCM
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