Ignition

P0357 — Ignition Coil G Primary/Secondary Circuit Malfunction

Severity: medium Drive with care, to a shop

What P0357 means

The engine computer fires each ignition coil through its own driver and monitors the primary circuit. P0357 is set when the signal for coil G does not match what is expected, due to an open, a short, or a coil that does not respond. Coil G usually serves cylinder 7, but confirm the exact layout for your engine.

Symptoms

  • Check Engine light on
  • Misfire on one cylinder
  • Rough idle
  • Weak acceleration and power loss
  • Higher fuel consumption
  • Hesitation or stalling under load

Possible causes

  1. Failed ignition coil G
  2. Open or short in the coil control wiring
  3. Poor connection or damaged coil connector
  4. Faulty coil driver inside the PCM
  5. Corroded or damaged power or ground circuit

How to diagnose

  1. Scan codes and freeze frame data and look for related misfire codes (P0307, etc.)
  2. Identify which cylinder coil G serves using the layout for your engine
  3. Inspect the coil connector and harness for heat damage, corrosion or chafing
  4. Swap coil G with a neighboring coil and see whether the fault follows
  5. Check power and ground at the coil connector with a multimeter
  6. Check the PCM control signal with a scope or noid light
  7. Test the control wire from coil connector to PCM for opens and shorts
  8. If wiring and coil are good, suspect the PCM

Common fixes

  • Replace ignition coil G
  • Repair the wiring harness or replace the damaged connector
  • Replace a worn spark plug in that cylinder if it caused the coil failure
  • Replace or reflash the PCM (rare, after full diagnosis)

P0357 on different brands

Ford · manuals
Ford documents an extended P0357:11 format in its 2024-2025 gasoline-engine diagnostic strategy, indicating a circuit short to ground; it describes the condition the monitor found, not a confirmed failed part.

Questions and answers

What does P0357 mean?

It means a fault in the primary or secondary circuit of ignition coil G, usually cylinder 7. The PCM saw the coil circuit behave abnormally and turned on the check engine light.

Can I drive with P0357?

Only briefly and gently. Misfires can overheat the catalytic converter, so repair it soon.

Is replacing the coil enough?

Often, but check the connector and wiring first, or the new coil may fail again. Swapping coils is a quick way to find the cause.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.