P0279
Cylinder 7 Injector A Circuit Low
Fuel injection / injector circuit
Generic OBD-II
High
What it means
P0279 means the ECM detected a low-voltage (short-to-ground or open) fault in the control circuit for cylinder 7's fuel injector. With the injector not firing correctly, cylinder 7 misfires and the engine runs rough and down on power. The fault is almost always in the injector wiring, its connector, or the injector coil itself.
High
Can I keep driving? Drivable but rough — cylinder 7 may not fire, causing a misfire and lost power; repair it before the catalytic converter is affected.
Common symptoms
What you'll notice
- Check-engine light on
- Misfire or rough running from cylinder 7
- Rough idle and vibration
- Reduced power and hesitation
Common causes
Most likely first
- Short-to-ground or open in the cylinder 7 injector control wiringLikely
- Corroded or loose injector connector on cylinder 7Common
- Failed injector coil/winding on cylinder 7Common
- Faulty injector driver in the PCM (rare — verify wiring first)Less often
How to diagnose & fix
Work through it in order
- Scan and read freeze-frame data to confirm the circuit is reading low (shorted or open).
- Inspect the cylinder 7 injector connector and wiring for shorts, chafing, and corrosion.
- Measure the injector's resistance and compare it against the other injectors and spec.
- Swap-test with a known-good injector if the coil is out of range.
- If wiring and injector are good, check the PCM driver circuit. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0279?+
Briefly, yes, but a dead injector means a persistent misfire that can overheat the catalytic converter. Repair it promptly.
Can I just clear P0279?+
It returns as soon as the circuit fault recurs. The wiring, connector, or injector on cylinder 7 needs repair first.
Related codes
Often seen with P0279
Read & clear P0279 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