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P3466 OBD-II Trouble Code: Cylinder 9 Deactivation/Intake Valve Malfunction

Check Engine Light

P3466 code definition

P3466 is code for Cyl9 Deactivation/Intake Valve Ctrl Perf. Cyl9 narrows the issue down to engine cylinder number 9, while “Perf” indicates a performance problem. Other P3400 series codes may also be present, alerting you to an issue with another cylinder.

What the P3466 code means

In order to maximize fuel economy, protect the engine from undue stress, and reduce emissions, most late model vehicles with more eight or more cylinders feature a deactivation process that turns off half of the cylinders when the vehicle is operating under light load conditions. This happens by way of the MAF (mass airflow), MAP (manifold absolute pressure), and TP (throttle pressure) sensors telling the ECM to turn off the fuel injectors to certain cylinders. When cylinder 9 fails to deactivate, the intake valve which provides fuel to the engine doesn’t shut down the way it’s supposed to. The ECM receives a message about this failure and kicks out the P3466 code.

What causes the P3466 code?

The causes of this code range from minor malfunctions to major issues, and may include:

  • A bad sensor, such as the mass airflow sensor or manifold absolute pressure sensor
  • A bad deactivation solenoid
  • A short in the wiring or harness
  • Poor fuel pressure
  • A valve lifter malfunction
  • Low oil pressure
  • A loose deactivation solenoid connection
  • A mechanical problem in the engine

Very rarely, a faulty PCM may be to blame; however, this is rarely the cause of a deactivation fault.

What are the symptoms of the P3466 code?

When a cylinder doesn’t deactivate as it should, the ECM will shut off the cylinder, which may cause misfires and/or vibrations when the vehicle is running. The Service Engine Soon light may come on as well.

How does a mechanic diagnose the P3466 code?

The mechanic will make sure the vehicle has proper oil levels and pressure, followed by verifying the Diagnostic Trouble Codes using a scanner, assessing and diagnosing any other codes that are stored in the powertrain control module at the same time. The codes should then be cleared from the scanner. The mechanic will then test the cylinder deactivation solenoid using a scan tool. If the solenoid is malfunctioning, the oil passages will be checked and cleared of debris and other obstructions. If your technician determines that the solenoid is functioning and there are no oil blockages, the valve lifters may be the source of the problem.

Common mistakes when diagnosing the P3466 code

Replacing parts without following the entire recommended diagnostic procedure can result in costly repairs without solving the problem. The oil passageways can easily be overlooked when diagnosing this code – these should always be checked for any possible obstruction.

How serious is the P3466 code?

Any time you get a code related to the deactivation system, particularly if your vehicle is exhibiting observable symptoms, you should have it diagnosed and repaired as soon as possible. While the vehicle will likely still run, the engine won’t function as it’s supposed to, which can cause damage in the future.

What repairs can fix the P3466 code?

Fixing a deactivation solenoid performance problem may include:

Additional comments for consideration regarding the P3466 code

The process of narrowing down exactly what’s causing a deactivation control malfunction can be painstaking, and requires specialized tools like a scanner that can give additional information about the fault. In addition, if the entire engine must be taken apart to clean the oil passageways, this is a major undertaking that requires a high level of automotive knowledge. It is always best to consult a professional if you have doubts about attempting this repair on your own.

Need help with a P3466 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

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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