P02F4
Cylinder 7 Injector Circuit Range/Performance
Fuel injector circuit
Generic OBD-II
High
What it means
P02F4 means the ECM sees the electrical signal to (or feedback from) the cylinder-7 fuel injector fall outside its expected range. The injector may fire weakly, erratically, or not at all, so cylinder 7 can misfire — causing rough running and lost power. It usually points to the injector wiring, the injector itself, or its driver circuit.
High
Can I keep driving? Drivable, but a weak or dead cylinder-7 injector means a misfire — keep trips short and gentle until it's fixed to avoid catalytic-converter damage.
Common symptoms
What you'll notice
- Check-engine light on
- Rough running or a noticeable misfire, worse under load
- Reduced power and hesitation on acceleration
- Rough idle
Common causes
Most likely first
- Damaged, corroded, or loose wiring/connector at the cylinder-7 injectorLikely
- Faulty cylinder-7 fuel injector (out-of-spec resistance)Common
- Poor ground or supply to the injector driver circuitCommon
- Failed injector driver / control module (FICM on some diesels)Less often
- ECM fault (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm the fault is on cylinder 7.
- Inspect the cylinder-7 injector connector and harness for damage, corrosion, or a loose pin.
- Measure injector resistance against spec and compare with a known-good cylinder.
- Check the injector driver's supply and ground circuits.
- Replace the injector if it is out of spec; if wiring and injector are good, suspect the injector driver module or ECM. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P02F4?+
Short trips are usually okay, but an erratic or dead injector causes a misfire that can overheat the catalytic converter, so fix it promptly.
Can I just clear P02F4?+
You can, but it returns until the injector circuit fault is repaired.
Related codes
Often seen with P02F4
Read & clear P02F4 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX