What it means
The drive circuit for the cylinder 8 alternative-fuel injector is open. Bi-fuel vehicles have a second set of injectors for CNG, LPG, or hydrogen — separate from the petrol/diesel injectors.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Bi-fuel vehicles use a separate alternative-fuel injector for each cylinder in addition to the petrol or diesel injectors. P22F5 indicates an open drive circuit to the alternative-fuel injector on cylinder 8, so it may not operate when the engine is using alternative fuel.
Common causes
Most likely first.
- Injector winding open
- Pin pushed back out of connector body
- Cracked solder joint inside the module or sensor
Symptoms
- Check engine light on
- Misfire or rough idle on the affected cylinder
- Increased fuel consumption
- Possible fuel smell or smoke from exhaust
How to diagnose it
- Save freeze-frame data and check live misfire data for cylinder 8, noting whether the fault appears during alternative-fuel operation.
- With the engine off, inspect the cylinder 8 alternative-fuel injector connector for a loose plug or a terminal pushed back into the connector body.
- Check the cylinder 8 injector harness for a break, chafing, or a damaged splice between the injector and control module.
- Test circuit continuity and the injector winding using the manufacturer's procedure to locate the open.
- If the injector and harness are intact, test the control-module connector and driver using manufacturer guidance.
Common fixes
- Reseat the cylinder 8 injector connector and secure any backed-out terminal.
- Repair an open or damaged wire in the cylinder 8 injector circuit.
- Replace the cylinder 8 alternative-fuel injector if its winding is open.
- Repair or replace the control module if its cylinder 8 driver is confirmed faulty.
Can I keep driving?
If the vehicle runs normally on its other fuel, use that mode only if the vehicle permits it and the fuel system is operating normally; avoid alternative-fuel operation until repaired. A cylinder 8 misfire can worsen fuel economy and emissions and may damage the catalyst.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.