P0261
Cylinder 1 Injector A Circuit Low
Fuel injector circuit
Generic OBD-II
High
What it means
P0261 means the ECM has detected low voltage — typically a short to ground — in the control circuit for the cylinder 1 fuel injector. If the circuit fails, cylinder 1 stops firing and the engine misfires, runs rough, and loses power. The usual cause is shorted wiring, a bad connector, or a failed injector.
High
Can I keep driving? Drive as little as possible — a low-voltage/short fault in the cylinder 1 injector circuit can kill that cylinder, causing a heavy misfire, rough running and possible stalling.
Common symptoms
What you'll notice
- Check-engine light on
- Misfire, rough idle, or shaking from a dead or weak cylinder 1
- Reduced power and hesitation on acceleration
- Rough running and, on some engines, stalling
Common causes
Most likely first
- Injector control wire shorted to ground (most common for a 'low' code)Likely
- Corroded, loose, or damaged connector at the cylinder 1 injectorCommon
- Failed fuel injector with a shorted coilCommon
- Faulty ECM injector driver (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame and confirm the circuit-low/injector fault is on cylinder 1.
- Inspect the injector wiring and connector for a short to ground, chafing, or corrosion.
- Measure the injector coil resistance against spec and compare with a known-good cylinder.
- Swap the suspect injector with a neighbouring one; if the fault follows, replace the injector.
- Verify the ECM's injector driver is functioning before condemning it, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0261?+
Keep it brief. A dead cylinder 1 means a heavy misfire that wastes fuel and can overheat the catalytic converter, so fix it promptly.
Can I just clear P0261?+
It returns as soon as the short or injector fault is seen again. Repair the wiring or injector first, then clear it.
Related codes
Often seen with P0261
Read & clear P0261 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