Powertrain, generic (extended)

P22F7 Cylinder 8 Alternative Fuel Injector Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P22F7 means the drive line of the cylinder 8 gas injector cannot be pulled down and stays near supply voltage. Ford lists it with MIL in the 2014 code list; in the conversion data from Altech-Eco/TransEco the cause given is a short to power, keeps the MIL off on dedicated CNG engines and marks the fault as not detectable by gas module version 1.4. Many output stages shut themselves off under such a short to protect the driver, so the valve stays closed and cylinder 8 runs without gas. A bi-fuel truck usually leaves gas mode and drives on gasoline; a dedicated CNG engine keeps misfiring. Check for a pinched wire touching a supply line before replacing the valve or module.

Likely causes

Cylinder 8 control wire pinched against a supply line
Supply and control pins swapped in the gas harness
Damaged output stage in the control module

Symptoms

  • Cylinder 8 lean misfire in gas mode
  • Check engine light on (bi-fuel versions)
  • Vehicle stays on gasoline

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–600
Time0.5–3 h

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

Parts involved

alternative fuel injector

Related codes

P22F5P22F6P22F8P22F3P0208

References: http:, performanceparts.ford.com, law.cornell.edu.