What P0357 means
P means powertrain (engine and transmission). The 0 marks a generic code defined by SAE, so the same number means the same thing across makes. The third character, 3, places it in the ignition system or misfire subsystem; the last two digits identify the specific fault.
Modern engines use one coil per cylinder (or per pair), each switched by the engine computer or an ignition module. These codes monitor the coil's primary or secondary circuit. The letter identifies a coil driver; on many engines coil "A" serves cylinder 1, "B" cylinder 2 and so on, but the manufacturer defines the assignment.
What “Circuit” means here
"Circuit" is the broadest fault type in the standard. The module has found the ignition coil circuit circuit electrically unusable: the signal is missing, outside its electrical limits, or the module's own self-test of the circuit failed. Some vehicles set this instead of the more specific low/high codes; others set it alongside them. Either way the first suspect is the wiring and connector, then the component, and only then the module.
What you may notice
Symptoms depend on the vehicle and on how the module responds to the fault. Any of these can accompany P0357:
- Misfire on the associated cylinder
- Rough running and loss of power
- Flashing check engine light under severe misfire
Where to start diagnosing P0357
- Confirm which cylinder the coil serves from service information.
- Inspect the coil connector and wiring, and check for cracked coil boots or carbon tracking.
- Swap the coil with a neighbouring cylinder and see if the code or misfire follows it.
- Check the coil power feed and fuse.
Clear the code only after recording freeze frame data: it shows the engine speed, load and temperature at the moment the fault set, which is often the best clue to reproducing it.
Live data to watch
These standard OBD2 values relate to P0357. Support varies by vehicle; a value your car does not report will simply be missing.
| Value | What to look for |
|---|---|
| Engine RPM (PID 0x0C) | Idle stability. |
| Misfire counts | Mode 06 per-cylinder data on many vehicles. |
Related codes
Codes from the same ignition coil circuit family. If several are stored together, the shared part — wiring, a common reference voltage, or the component itself — is the place to start.
| Code | Definition |
|---|---|
| P0353 | Ignition Coil "C" Primary/Secondary Circuit |
| P0354 | Ignition Coil "D" Primary/Secondary Circuit |
| P0355 | Ignition Coil "E" Primary/Secondary Circuit |
| P0356 | Ignition Coil "F" Primary/Secondary Circuit |
| P0358 | Ignition Coil "H" Primary/Secondary Circuit |
| P0359 | Ignition Coil "I" Primary/Secondary Circuit |
| P0360 | Ignition Coil "J" Primary/Secondary Circuit |
| P0361 | Ignition Coil "K" Primary/Secondary Circuit |
Further reading
Frequently Asked Questions
What does P0357 mean?
P0357 is the generic SAE J2012 code for "Ignition Coil "G" Primary/Secondary Circuit". In plain terms, it means the engine computer has detected a "circuit" fault on the ignition coil circuit.
Can I keep driving with P0357?
An ignition fault causes misfires that can damage the catalytic converter. Limit driving until repaired.
What should I check first for P0357?
Confirm which cylinder the coil serves from service information.
Definition source: SAE J2012 / ISO 15031-6 generic DTC definitions. This is the generic meaning that applies across makes; a manufacturer can define a code more narrowly or add its own sub-codes, so confirm against the service information for your vehicle before replacing parts. Written by the OBDAssistant engineering team — see our editorial policy.