P0261 Code: Cylinder 1 Injector Circuit Low
P0261 means the fuel injector signal voltage for Cylinder 1 is too low. Check for short to ground in the wiring or a failed injector driver.
What does P0261 mean?
P0261 means the fuel injector signal voltage for Cylinder 1 is too low. Check for short to ground in the wiring or a failed injector driver. When this code is set, the engine computer has detected a condition that falls outside its expected parameters for normal operation.
Common causes of P0261
The most frequent causes of a P0261 code fall into four categories:
- Component failure — worn sensors, failed relays, or aging parts that can no longer produce reliable signals.
- Wiring and connectors — corroded pins, chafed wires, or loose ground points that break the signal chain.
- Mechanical issues — vacuum leaks, exhaust leaks, or fuel delivery problems that affect the sensor readings.
- Software and calibration — occasional ECU glitches after battery disconnection or updates.
Run the AI-powered diagnostic tool below to get vehicle-specific causes, ranked by likelihood.
How to diagnose P0261
- Read the full scan — any codes stored alongside P0261 usually point to the real cause.
- Inspect the most commonly associated components for visible damage or wear.
- Check wiring and connectors for corrosion or breaks.
- Test with a multimeter or scope where relevant.
- Confirm by clearing the code and driving a complete drive cycle.
How serious is P0261?
The severity depends on the underlying cause. In most cases, P0261 doesn't stop the vehicle running — but ignoring it can cause further damage, reduced fuel economy, and failure of a roadworthy or emissions inspection. Get it diagnosed within a few hundred kilometres.
Can I drive with P0261?
Short-term driving is usually fine. Avoid long trips or heavy loads until diagnosed — some underlying faults can escalate to expensive repairs if left unchecked.
