Powertrain, generic · Ignition system or misfire

P0357 Ignition Coil G Primary Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

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).

Likely causes

Ignition coil G faulty (output stage in the coil or primary winding open)
Connector at the coil corroded, wet or with a loose pin
Control, supply or ground wire open or chafed
Driver in the engine module faulty or software (permanent dwell)

Symptoms

  • 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

Repair estimate

DifficultyEasyDIY possible
Parts and labour€40–250
Time0.3–1.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

ignition coil gignition wiringengine control module

Related codes

P2318P2319P2320P0350P0307P0300

References: gsi.ext.gm.com, gsi.ext.gm.com, newtonnet.co.uk, fordservicecontent.com.