Powertrain, generic · Ignition system or misfire

P0356 Ignition Coil F Primary Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P0356 monitors the primary control circuit of ignition coil F – the line from the engine module to the coil or to its built-in output stage – for an open circuit or high resistance. Coil F usually serves cylinder 6, so the code only occurs on engines with at least 6 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 PIP5038B describes coils on the 3.6-litre V6 (LLT) overheating from a permanently switched-on control signal; PIP5147 advises checking coil connectors for water. Short circuits have their own codes (P2315 ff).

Likely causes

Ignition coil F 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 6, often also P0306
  • 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 fignition wiringengine control module

Related codes

P2315P2316P2317P0350P0306P0300

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