P22D9 code meaning
Cylinder 1 Alternative Fuel Injector Control Circuit/Open
Powertrain system Generic code P22xx codes Check engine light
What P22D9 means
P22D9 reports a broken control circuit at the gas injector of cylinder 1, the solenoid that meters CNG or LPG into the intake port whenever a bi-fuel or dedicated gas engine runs on the alternative fuel. The driver stage notices the break because no current flows when it switches on, or because the expected off-state voltage on its pin is missing. No maker publishes P22D9 itself: the TransEco AFCM list and Ford's 2014 code list only carry the Low/High pair P22DA/P22DB, and TransEco even files an open line under Low. GM's bi-fuel Silverado moves the injectors over to gas one by one starting with cylinder 1, so a break here tends to show up right at the changeover. Bi-fuel cars usually return to gasoline; a dedicated gas engine loses cylinder 1.
P22D9 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P22D9
- Malfunction indicator lamp on
- Engine changes back to gasoline or refuses to switch to gas
- Misfire on cylinder 1 in gas mode (dedicated engines)
Common causes of P22D9
- Most likelyOpen solenoid winding in the cylinder 1 gas injector
- PossibleLoose, corroded or unplugged connector at the gas injector
- PossibleBroken wire or failed splice in the gas system harness
- Less likelyDefective driver stage in the gas or engine control module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Alternative fuel injector
What each part of P22D9 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 2 | Area: fuel and air metering (injector circuit). |
| D9 | The exact fault in that area. |
What to do next
- Note P22D9 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P22D9
What does P22D9 mean?
P22D9 means "Cylinder 1 Alternative Fuel Injector Control Circuit/Open". P22D9 reports a broken control circuit at the gas injector of cylinder 1, the solenoid that meters CNG or LPG into the intake port whenever a bi-fuel or dedicated gas engine runs on the alternative fuel. It is a generic code, so it means the same on every make.
Is it safe to drive with P22D9?
Drive gently and only to a workshop. With P22D9 the car can go into limp mode (reduced power) to protect itself.
Will P22D9 fail an emissions test?
Yes, it can. P22D9 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P22D9 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. This is a job for a workshop.
Will P22D9 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.