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P3446 OBD-II Trouble Code: Cylinder 6 Exhaust Valve Control Performance

P3446 code definition

The P3446 code indicates that the PCM has detected a range of voltage values from the mass airflow sensor, the intake control manifold absolute pressure sensor, and the throttle position sensor, all within cylinder 6, that are not within the correct range, as compared to the manufacturer’s specifications. This code is very similar to the P3478 code, which represents the same issue within cylinder 10.

What the P3446 code means

In order to provide maximum fuel efficiency, certain cylinders are shut down during specific driving conditions. The PCM will instruct the cylinder deactivation solenoids to begin the process, which involves restricting the flow of oil to the valve lifts, which then stops the exhaust valve from opening. Using the data from the various sensors, the PCM can tell if the exhaust valve is operating normally. If the data does not match the specified voltage reading, the PCM will store the P3446 code.

What causes the P3446 code?

The P3446 code could be caused by any of the following:

  • Low oil pressure
  • Faulty throttle position sensor
  • Clogged oil passages
  • Faulty lifters
  • Faulty cylinder deactivation solenoid
  • Faulty mass airflow sensor, or faulty intake control manifold absolute pressure sensor
  • Faulty electrical components within the circuit, including wiring, harnesses, or connectors

What are the symptoms of the P3446 code?

In addition to the illuminated Check Engine Light, drivers may notice that the engine vibrates during operation.

How does a mechanic diagnose the P3446 code?

With this type of code, it is important to check the PCM for other stored codes, and to diagnose and repair those codes first. If after repairing any other codes within the PCM, the P3446 code is still reappearing, then the mechanic should check the engine oil pressure and oil levels. A visual inspection of all electrical components should follow, and any damaged elements should be repaired or replaced as necessary.

The code should be cleared from the PCM, and the system should be retested after each potential repair. The next step is to test the cylinder deactivation solenoid using a scan tool, and then to examine the oil passages for any debris that could be clogging them. Finally, the solenoid should be replaced if none of the other repairs have diagnosed the issue.

Common mistakes when diagnosing the P3446 code

The biggest mistake reported by technicians is forgetting to check the oil passages for clogs. This can cause a decrease in oil pressure, which prevents the cylinder deactivation solenoids from operating correctly. These passageways should always be checked and cleared if necessary.

How serious is the P3446 code?

This code represents an issue that should be repaired as soon as possible. If the P3446 code is ignored, it can lead to heavy damage to other areas of the engine, which can lead to expensive repairs in the future.

What repairs can fix the P3446 code?

In order to repair the P3446 code, a mechanic may attempt any of the following:

Need help with a P3446 code?

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