P0357Ignition Coil G Primary Control Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P0357 monitors the primary control circuit of ignition coil G – the line from the engine module to the coil or to its built-in output stage – for an open circuit or high resistance. Coil G usually serves cylinder 7, so the code only occurs on engines with at least 7 cylinders. GM's 6.2-litre V8s (LT4, LT5) flag an open circuit above 30 kΩ with the driver off in 50 of 63 samples, after two trips. Ford checks continuously from 200 rpm within 1 s, expecting a primary-current feedback for every ignition command, and then shuts off injection to that cylinder for 30 s at a time to protect the catalyst. GM bulletin PIP5147 for 2014 Silverado and Sierra trucks advises checking the coil connectors for water and discoloration and swapping the coil to another cylinder to see whether the fault follows. Short circuits have their own codes (P2318 ff).
- What you may notice
- Check engine light on
- Misfire and rough running on cylinder 7, often also P0307
- Loss of power, jerking under load
- Cylinder shut off (injection off), risk to the catalyst if driven on
- Likely causes
- LikelyIgnition coil G faulty (output stage in the coil or primary winding open)
- LikelyConnector at the coil corroded, wet or with a loose pin
- PossibleControl, supply or ground wire open or chafed
- RareDriver in the engine module faulty or software (permanent dwell)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €40 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.