How much does it cost to fix P0261?

DIY repair typically costs $15–$150 for parts. Professional repair runs $100–$500 including parts and labor.

P0261

Powertrain

Moderate

Cylinder 1 Injector Circuit Low

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The P0261 code indicates that the PCM has detected a lower-than-expected voltage in the electrical circuit controlling the cylinder 1 fuel injector. This is a circuit-level fault — meaning the problem is electrical in nature, not necessarily related to fuel delivery or combustion directly. The low voltage can mean the injector isn't firing properly or at all, which will cause a misfire on that cylinder.

The most common cause is simply a loose or corroded electrical connector at the injector. Fuel injector connectors are exposed to significant engine heat and vibration, and over time the connection can degrade. The wiring harness between the PCM and injector is another frequent failure point, as wires can chafe against engine components and short to ground. The injector itself may also have a shorted internal coil.

Start diagnosis by inspecting the connector at cylinder 1's fuel injector — clean any corrosion and ensure a firm connection. If that doesn't resolve it, check the wiring harness for damage. A resistance measurement of the injector coil compared to specifications will determine if the injector needs replacement. This repair is generally DIY-friendly since fuel injectors are easily accessible on most engines.

Severity

Moderate — Address SoonThis Week

Symptoms

•Engine misfires or runs rough, especially at idle
•Noticeable loss of power during acceleration
•Check Engine Light is on or flashing
•Poor fuel economy
•Fuel smell from the exhaust

Likely Causes

Loose or corroded injector electrical connector35%

The most common cause of a low-circuit condition is a loose, corroded, or damaged electrical connector at the cylinder 1 fuel injector. Vibration and heat cycling can loosen connections and promote corrosion over time.

Shorted injector wiring harness25%

The wiring harness running from the PCM to the injector can develop shorts to ground from chafing against engine components, heat damage, or rodent damage, pulling the circuit voltage below specification.

Faulty fuel injector (shorted coil)25%

The injector's internal solenoid coil can develop a short circuit, reducing resistance below normal range. This causes the PCM to detect a low-circuit condition as the injector draws more current than expected.

PCM injector driver fault15%

The PCM uses internal transistor drivers to control each fuel injector. If the driver for cylinder 1 is damaged or leaking current to ground, it can register a low-circuit reading even with a good injector.