What it means
The cylinder 7 alternative-fuel injector control circuit has a voltage below the expected range. This indicates an electrical circuit fault, not necessarily an injector flow problem or short to ground.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The control module switches the alternative-fuel injector for cylinder 7 through its own electrical circuit. P22F2 sets when circuit voltage is below the expected range; this identifies a low-voltage electrical condition, not necessarily a short to ground or a fuel-flow problem.
Common causes
Most likely first.
- Short to ground
- Connector pins corroded - high contact resistance
- Harness chafing through insulation
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 7 to see whether the low-voltage fault coincides with rough running.
- Inspect the cylinder 7 alternative-fuel injector connector and harness for corrosion, loose pins, or insulation worn through against the body or another ground.
- Compare cylinder 7 circuit readings with the manufacturer's diagnostic information to confirm the low condition.
- With power isolated as specified by the manufacturer, check the control circuit for an unintended ground and inspect terminal contact quality.
- If the wiring and connector 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 chafed insulation or a control wire shorting to ground in the cylinder 7 circuit.
- Replace the cylinder 7 alternative-fuel injector if its electrical tests fail.
- Repair or replace the control module only if its cylinder 7 driver is confirmed faulty.
Can I keep driving?
If the engine is running roughly, avoid continued driving and heavy acceleration; if it runs normally, drive only as needed for prompt diagnosis. A cylinder 7 misfire can increase emissions and fuel use and 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.