P0261 means Cylinder 1 Injector Circuit Low. The cylinder 1 injector circuit voltage is lower than expected, usually from a short to ground on the control side. It is a generic OBD-II code, so the definition is the same on any make, but the most likely cause varies by engine; confirm with a scan tool and the service information for your vehicle before buying parts.
What P0261 means
Each fuel injector is a small solenoid that the engine computer switches on and off many times a second. The computer monitors every injector circuit for opens and shorts, and an injector circuit fault usually comes with a misfire on the same cylinder because that cylinder gets no fuel.
P0261 symptoms
- Misfire on cylinder 1
- Rough idle
- Check engine light
Common causes of P0261
- Wiring shorted to ground
- Shorted injector coil
- Damaged connector
How to diagnose P0261
- Inspect the harness for chafing
- Measure injector resistance
- Check the circuit for shorts with the connector unplugged
Can you drive with P0261?
Only briefly.
P0261 tips
A short to ground on the control side can make the injector stay open; fix it promptly because it can flood the cylinder and dilute the oil with fuel. Check the oil level and smell after the repair, and change the oil if it smells of fuel. Inspect the harness where it runs near the intake and fuel rail, where heat and vibration wear through insulation.
Will P0261 clear itself?
If the fault stops, the computer turns off the check engine light by itself after several drive cycles without seeing it again, and the code stays in memory as history for a while. Clearing P0261 with a scan tool after a repair is fine, but if the cause is still there the code returns, sometimes within one drive. Disconnecting the battery also clears codes on most vehicles, but it erases learned fuel trims and idle settings as well.
Related codes
| Code | Meaning |
|---|---|
| P0201 | Injector Circuit/Open – Cylinder 1 |
| P0262 | Cylinder 1 Injector Circuit High |
| P0301 | Cylinder 1 Misfire Detected |
Guides that help
When it is more than a sensor
If an injector and its wiring test good but the cylinder still misfires, a compression test separates a fuel problem from a mechanical one; see engine replacement cost and our engines page if the engine is worn.
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