P22DC is meant for a cylinder 1 gas injector whose circuit is electrically intact but whose response looks wrong, such as a current trace that never reaches its peak or does not fall back to the hold level, or a coil whose resistance has drifted. A Ford patent on driving a second type of injector through an interface (US 8,161,946) describes this logic: the injector counts as degraded if it ignores on and off commands or stays at peak current. No vehicle maker publishes P22DC; TransEco and Ford's 2014 list stop at Low/High. A sticking injector is a plausible trigger, which is why GM's bi-fuel pickups filter the gas through a coalescing element that keeps oil and liquids away from the injectors. Expect a misfiring cylinder 1 or a return to gasoline.
High severity. Can I keep driving?If you smell gas, do not keep driving or start the engine: move away and call for assistance. With no smell, drive moderately to an authorized shop.
Cylinder 1 is numbered according to the manufacturer: check your engine's manual before working on it.
Symptoms
- Malfunction indicator lamp on
- Uneven running in gas mode, misfire counts on cylinder 1
- Higher gas consumption or switch back to gasoline
Most likely causes
- Cylinder 1 gas injector sticking from oil residue or debris in the gas
- Injector coil resistance outside its specification
- Weak supply voltage to the injector bank
- Injector of the wrong type or impedance installed
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It can trigger limp mode.
- It affects emissions.
What each character of P22DC means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- 2: Fuel injection
- DC: Specific fault in that system
Frequently asked questions
Can I keep driving with code P22DC?
If you smell gas, do not keep driving or start the engine: move away and call for assistance. With no smell, drive moderately to an authorized shop.
What causes code P22DC?
The most common causes are: cylinder 1 gas injector sticking from oil residue or debris in the gas; injector coil resistance outside its specification; weak supply voltage to the injector bank.
Related codes
- P22D9Cylinder 1 Alternative Fuel Injector Control Circuit/Open
- P22DACylinder 1 Alternative Fuel Injector Control Circuit Low
- P22DBCylinder 1 Alternative Fuel Injector Control Circuit High
- P22E0Cylinder 2 Alternative Fuel Injector Control Circuit Range/Performance
- P0201Cylinder 1 Injector A Circuit/Open
- P0301Cylinder 1 Misfire Detected
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.