Cylinder 1 Injector Circuit Low
What does P0261 mean?
The P0261 code means the vehicle's onboard diagnostic system has detected: Cylinder 1 Injector Circuit Low. This is a moderate severity code.
Common Symptoms
- Engine misfire on cylinder 1
- Rough idle
- Check Engine Light illuminated
- Reduced power and poor acceleration
- Strong fuel smell from exhaust
Probable Causes (Ranked by Likelihood)
- Short to ground in cylinder 1 injector wiring Very High
- Faulty cylinder 1 fuel injector (shorted coil) High
- Corroded injector connector pins High
- Damaged wiring harness near injector Moderate
- PCM injector driver circuit failure Low
Step-by-Step Diagnostic Procedure
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Measure cylinder 1 injector resistance -- should be 11-18 ohms for high-impedance injectors; below spec indicates a shorted coil
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Check for short to ground by testing continuity between the injector signal wire and engine ground with injector disconnected
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Swap cylinder 1 injector with cylinder 2 and clear codes -- if the code follows the injector, replace it
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Inspect the injector wiring harness for chafed or melted insulation near exhaust components
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If wiring and injector test good, test the PCM injector driver output with a noid light
Frequently Asked Questions
Can I drive with code P0261?
You can drive short distances, but the engine will run on fewer cylinders causing rough operation and potential catalytic converter damage from unburned fuel.
What does injector circuit low mean?
It means the PCM detects lower than expected voltage or resistance in the fuel injector circuit for cylinder 1, usually caused by a short to ground in the wiring or a shorted injector coil.
Can I swap injectors to test?
Yes. Swapping the suspect injector with one from another cylinder is an excellent diagnostic technique. If the code moves to the other cylinder, the injector is faulty.