Cars were not designed to run efficiently forever. They require maintenance and sometimes even develop faults that have to be attended to before they can return to optimal operation.
When a car starts giving off strange symptoms, diagnosing the car with a scanner might be a good way to confirm the actual fault of the vehicle. The scanning process can easily be done at home without a mechanic’s help.
What does this mean for your car if you scan your Honda Pilot and notice the P3400 code? Keep reading to find out.
What does it mean?
The P3400 code means there is an issue with the cylinder deactivation system of your car. Most times, the cause for a P3400 on your Honda is low-level engine oil.
However, there can be other reasons as well, which I will discuss in this article.
Should you worry about this? Not really. Your car can function perfectly on all its cylinders; hence loss of its ability to reduce its use of all cylinders will not affect its performance in any way.
However, you should not dismiss this issue as the possible causes might result in engine failure if left unattended for a long time. Therefore this generic Diagnostic Trouble Code (DTC) should be treated with severity.
Cylinder deactivation is a feature on modern cars that permits them to drop the full use of their cylinders to use just part of them. This feature is included in vehicles to increase fuel economy. How does it work?
When your Honda Pilot does not need maximum power, the system cuts down the use of part of its cylinders to reduce fuel use. Then, the moment more power is required, the car resumes full use of its cylinders.
A stored P3400 DTC implies that the Powertrain Control Module (PCM) has found a cripple with the cylinder deactivation system of engine bank one, and bank one contains the number one cylinder.
An issue with this system is not specific as there are multiple factors that keep this system in motion; thus, considering the main causes of this DTC might help in your investigation.
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Here are the main causes
There are multiple reasons for which the cylinder deactivation system can be disabled, therefore, it is required to inspect various components.
01. Low oil level
If P3400 was prompted after a scan, the first thing you should check before inspecting other parts of the car is to check your oil level. Most systems don’t function properly when the oil level is low; hence that might be the issue with your Honda Pilot cylinder deactivation system.
Any modern car will warn you if the engine oil level is low by illuminating the oil light.
Many people are unaware that cars require not just gas to operate normally and are only aware of this fact when a low oil level disrupts the car’s operations. If the oil level is the cause, filling up the oil with the recommended oil brand will clear the error code.
02. Faulty rear oil pressure sensor
Oil pressure sensors are another common cause and should be the next place to check after the oil level.
Low oil pressure could also disrupt the cylinder deactivation system. You can easily check the oil pressure by using an oil pressure gauge. If your oil pressure is appropriate, your rear oil pressure sensor might be the issue. The car’s PCM observes and detects problems with the car’s systems based on the data received from sensors at different parts of the vehicle.
This implies that even with the oil pressure in your engine at the right level, if the sensor reports false data, the PCM draws an inaccurate conclusion. Therefore, faulty oil pressure sensors should be replaced to clear the DTC.
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03. Defective valve timing control solenoid
The valve timing control solenoids play a vital role in the cylinder deactivation process; hence if they’re faulty, the process might not occur and thus lead to the generic DTC. The solenoids shut down the intake and exhaust valves of the deactivated cylinders.
If the valve timing control solenoids cannot close the valves, the cylinders will work normally instead of being disabled.
04. Bad wiring to the VVT system
Bad wiring could also cause the P3400 code. Therefore, inspect the wires that connect to the VVT system. Any frayed, broken, or burnt wires should be replaced immediately to clear the code.
Other causes include:
- Faulty mass airflow sensor
- Limited oil passage
- Faulty throttle position sensors
- Bad lifters
- Defective electrical connection in the solenoid circuit
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Symptoms of P3400
If your Honda Pilot’s cylinder deactivation system is faulty, you might not notice pronounced symptoms. You might have to pay close attention to your car to pick up other irregularities.
- Misfiring might occur.
- Illumination of the check engine light.
- Increased fuel consumption.
- More DTCs might also appear, such as VVT codes, misfire codes, and oil pressure codes.
How to fix P3400
After diagnosing your Honda Pilot, ensure the code is because of a mechanical fault before proceeding with repairs. The oil passageways sometimes become filled with debris and sludge, thus reducing oil pressure and reducing the operation of lifters and the valve timing control solenoid. Clearing the oil passageways may save you the cost of unnecessary repairs.
Use the OBD II scanner to check for other PCM saved codes. This might save time and point you in the right direction for repairs. For instance, oil pressure codes alongside the P3400 might indicate that the oil pressure is insufficient to activate the cylinder deactivation system.
Faulty parts should be repaired or replaced. These include wirings, defective sensors, bad solenoids, etc. Consult the help of an expert to oversee necessary repairs and replacements.
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Numerous issues could arise with the cylinder deactivation leading to the P3400 DTC. Resolving these issues helps to reinstate the cylinder deactivation system and clear the error code. In most cases, the cylinder deactivation system is completely fine, and a low oil level is the cause of the issue.
Therefore, before looking into other areas, check your oil level first. If your oil level is normal, you can then proceed with your investigations.