Powertrain, generic · Fuel and air metering (injector circuit)

P0212 Cylinder 12 Injector A Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0212 reports an electrical fault, mainly an open circuit, in the injector circuit of cylinder 12. The engine module watches each injector output: GM flags an open circuit at an impedance of 200 kΩ or more – on direct injection and diesel engines in 10 of 20 or 5 of 10 samples and with the warning light in the first trip, on some port-injected engines only after two trips. Ford's port injection reads a fault bit from the driver chip that covers open, short to ground and short to voltage alike; Ford diesels report only the open circuit here and shorts as P0294/P0295. Cylinder 12 exists only on twelve-cylinder engines. No publicly available manufacturer document using this code was found; the description follows the documented codes for cylinders 1–10 and CARB's circuit monitoring requirement.

Likely causes

Connector at the cylinder 12 injector loose, corroded or with a broken or pushed-back pin
Injector coil open
Wire between module and injector open or chafed (heat, rodents)
Injector supply missing (fuse, relay) – then usually several cylinders at once
Driver stage in the engine module faulty

Symptoms

  • Check engine light on
  • Misfire and rough running, misfire code P0312
  • Loss of power, rough idle
  • Limp mode possible on diesel and direct injection

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–900
Time1–5 h

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

Parts involved

fuel injector cylinder 12injector wiringengine control module

Related codes

P0294P0295P02F9P0312P0300P021F

References: law.cornell.edu, gsi.ext.gm.com.