What it means
The cylinder 7 alternative-fuel injector control circuit has a voltage above the expected range. This indicates an electrical circuit fault, not necessarily an injector flow problem or short to battery.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The alternative-fuel injector on cylinder 7 is switched by a dedicated control-module driver. P22F3 sets when the voltage in that injector's control circuit rises above the expected range, pointing to an electrical fault rather than confirming an injector flow problem.
Common causes
Most likely first.
- Short to B+
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
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
- Record freeze-frame data and check live misfire data for cylinder 7 to understand when the high-voltage condition occurs.
- With the engine off, inspect the cylinder 7 alternative-fuel injector connector and harness for corrosion, loose pins, or wiring pinched against a power source.
- Compare cylinder 7 control-circuit readings with the manufacturer's diagnostic information to verify the high condition.
- With power isolated as specified by the manufacturer, check for an unintended connection from the control circuit to B+.
- If the wiring and connections pass, test the cylinder 7 injector and control-module driver using the manufacturer's procedures.
Common fixes
- Clean or repair corroded terminals at the cylinder 7 injector connector.
- Repair a cylinder 7 control wire pinched against a B+ source.
- Replace the cylinder 7 alternative-fuel injector if its electrical test fails.
- Repair or replace the control module only if its cylinder 7 driver is confirmed faulty.
Can I keep driving?
If the engine runs smoothly, limit driving and avoid heavy acceleration until the fault is diagnosed. A cylinder 7 misfire can increase emissions and fuel use, and continued misfiring may damage the exhaust 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.