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

Our certified mechanics come to you · Get a fair and transparent estimate upfront


Cost of diagnosing the P3466 code

P3466 is a diagnostic trouble code (DTC) for "Cylinder 9 Deactivation/Intake Valve Malfunction". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic for $154.99 . Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $50.0 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate* Credit towards follow-up repair Earliest Availability
Ford $154.99 $50.0
Toyota $154.99 $50.0
BMW $164.99 $50.0

*Estimates may vary by market

SCHEDULE P3466 DIAGNOSTIC Get a fair and transparent estimate upfront

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.

Check Engine Light
trouble codes
P3466

No more waiting rooms! Our mechanics will come to you to diagnose and fix the P3466 code.

SCHEDULE P3466 DIAGNOSTIC
Get a $50 credit for the follow-up repair

Recent Check Engine Light is on Inspection reviews

Excellent Rating

(8600)

Rating Summary
8017
273
65
46
199
8017
273
65
46
199
 at YourMechanic

Brandon

9 years of experience
133 reviews
Brandon
9 years of experience
Ford Escort L4-2.0L - Check Engine Light is on - Nashville, Tennessee
Brandon showed up ahead of schedule, was very personable and diagnosed my problems. He also scheduled my next appointments which will be with him.
 at YourMechanic

William

23 years of experience
33 reviews
William
23 years of experience
Lexus IS250 V6-2.5L - Check Engine Light is on - Mableton, Georgia
Arrived early which was great. William was courteous, and attentive to the issue. Even though it took several attempts I'm so happy he was determined to fix it and he did!
 at YourMechanic

Dan

40 years of experience
1080 reviews
Dan
40 years of experience
Plymouth Grand Voyager - Check Engine Light is on - Lawrenceville, Georgia
Mr. Dan Barber was quite patient, courteous and quite knowledgeable. From my observation, Mr. Barber appears to be quite professional.
 at YourMechanic

Christopher

9 years of experience
120 reviews
Christopher
9 years of experience
Ford Fiesta L4-1.6L - Check Engine Light is on - Smyrna, Georgia
Chris communicated with us each step of the way up until his arrival. He listened well, was knowledgeable, and was prepared. He took the time to diagnose the problem, explained the what, why and how and provided a solution. I would definitely recommend him and will use him again.


More related articles

P0721 OBD-II Trouble Code: Output Speed Sensor Range/Performance
P0721 code means the transmission control module (TCM) isn't properly converting incoming pulse signals often due too poor, wiring or sensor.
P0895 OBD-II Trouble Code: Shift Time Too Short
P0895 code means that there is an abnormality in the shift time between individual gears due to transmission blockage, failure, or dirty fluid.
P0880 OBD-II Trouble Code: Traction Control Module (TCM) Power Input Signal
P0880 means that the TCM communication circuit is not communicating with the PCM due to a malfunction in the activation switch.

Related questions

Brakes went out in car
Hello, since you have a brake fluid leak (https://www.yourmechanic.com/services/brake-fluid-is-leaking-inspection), this needs to be repaired to make the car safe to drive. I would recommend not driving the car until this is fixed. You state that you hear something dragging, this...
Car went low on oil and now Check Engine Light and engine shaking
Well, a blinking Check Engine Light (CEL) is often more serious than a "steady" light because that typically means the engine is misfiring. You can't drive a misfiring engine very long without causing additional damage. The good news is there...
2008 Mazda 5 has codes P0661 and P0720
Input from the vehicle speed sensor (VSS) is used by the transmission control module (TCM) to calculate shift points, torque converter operation and other transmission functions. Code P0720 stands for Vehicle Speed Sensor circuit malfunction. Typically, this code indicates a...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com