P0261: Cylinder 1 Injector A Circuit Low
Do not keep driving
Expect rough running and lost power. Have it diagnosed promptly — a shorted injector can take the control module's driver circuit with it, turning a moderate repair into an expensive one.
What this code means
The injector drive circuit for cylinder 1 is reading low — a short to ground, or an injector winding that has failed short. A shorted injector can pull enough current to damage the module's driver stage, which is why this is worth resolving rather than driving on. Measure the injector's resistance at its own connector and compare against the others; a winding well below its neighbours is conclusive.
Likely causes
Start here
- Failed fuel injector · moderate
- Wiring shorted to ground · moderate
- Chafed harness against engine or bracket · moderate
Less common
- Corroded or loose connector · easy
- Control module driver failure · specialist
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
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