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P0261 OBD-II Trouble Code: Cylinder 1 Injector Circuit Low

Check Engine Light

P0261 code definition

Cylinder 1 Injector Circuit Low

What the P0261 code means

This trouble code indicates that the powertrain control module has detected a lower reference voltage coming from the number 1 cylinder’s fuel injector than what was specified by the vehicle manufacturer.

What are the causes of the P0261 code?

  • The fuel injector on the number 1 cylinder may have a broken or weak internal return spring which could cause the reference voltage level to decrease.

  • The wiring or connector that is associated with the number 1 cylinder could be having or causing a connection issue and connection issues may also cause voltage levels to decrease or become inaccurate.

  • The powertrain control module could be operating improperly.

What are the symptoms of the P0261 code?

Symptoms of this trouble code that the driver could potentially experience would include:

How does a mechanic diagnose the P0261 code?

  • A mechanic may diagnose this trouble code by locating the number 1 cylinder’s fuel injector.

  • Once the fuel injector on the number 1 cylinder has been located, the mechanic would test the fuel injector using the manufacturer’s suggested procedure. This test will reveal if the internal spring has failed due to the reference voltage that is produced by the fuel injector during this test.

  • Next, the mechanic would check the wiring and connector that are associated with the fuel injector on the number 1 cylinder for damages.

If the problem has still not been located after these tests have been performed, the powertrain control module may be at fault and would be tested by the mechanic. Once a determination has been made by the mechanic, he/she would share this information with the customer.

Common mistakes when diagnosing the P0261 code

A common mistake would be to replace the fuel injector on the number 1 cylinder without inspecting its circuitry for damages. Although a failed injector is the most common cause of this trouble code, it is not the only cause, therefore all other possible causes of this issue should be proven not to be the cause.

How serious is the P0261 code?

Any trouble code related to a malfunctioning fuel injector is a serious issue. This can affect the way your engine runs and, if put on the back burner, can cause engine damage. It is best to have this issue diagnosed and repaired as soon as possible in order to keep your vehicle’s engine in good running condition.

What repairs can fix the P0261 code?

  • Replacing the fuel injector on the number 1 cylinder

  • Repairing or replacing wiring or connectors that are associated with the fuel injector on the number 1 cylinder

  • Replacing the powertrain control module

Additional comments regarding the P0261 code

Regular fuel system maintenance such as fuel system cleanings can help to prevent obtaining a trouble code such as this. These cleaners will run through the fuel injectors, providing the lubrication that the small internal parts need to prevent the potential of broken return springs inside the fuel injector. This service should be done at least once a year but for best results, do it at every oil change.

Need help with a P0261 code?

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The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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