P22EC Cylinder 5 Alternative Fuel Injector Control Circuit Range/Performance

P22EC is the plausibility code for the cylinder 5 gas injector circuit on engines with five or more cylinders: wiring and coil pass the basic checks, but the injector does not respond as commanded. California's OBD rule requires such output components to be checked for a proper functional response, and from model year 2019 the maker of an alternate-fueled vehicle submits its own plan for which monitors apply. Ford's patent US 8,161,946 describes one way to do it, judging an injector by whether its current follows the peak-and-hold pattern. No maker publishes P22EC itself. A sticking armature, a heat-aged coil or a weak driver are the usual suspects. Bi-fuel cars may keep running on gas with a rough cylinder 5 or drop back to gasoline.

Likely causes

Symptoms

• Malfunction indicator lamp on
• Rough cylinder 5 on gas or return to gasoline
• Fuel trim on the affected bank drifts in gas mode

Repair estimate

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

Parts involved

Related codes

References: law.cornell.edu, patents.google.com.