What Is the P3400 Code?
Symptoms
Causes
Seriousness
Can I Still Drive?
Diagnose
Difficulty of Inspecting
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Many vehicles have four cylinders, which are the part of the engine that actively creates power. However, cars with six or eight cylinders can provide more power to the engine. The problem is that if you’re cruising or running your vehicle at a very low speed, you don’t need all of those cylinders, and the vehicle will deactivate the extra cylinders to save you fuel and money. The P3400 code indicates that the deactivation system has somehow malfunctioned.
More About the P3400 Code
The P3400 code is extremely broad, and it indicates only that something has gone wrong with cylinder deactivation. That means it should come with extra codes that will indicate exactly what has gone wrong. Those codes tend to be P3401-P3404, P3409-P3412, P3417-P3420, P3425-P3428, P3433-P3436, P3441-P3444, P3449-P3452, and P3457-P3460. These areas indicate not only the specific cylinder that’s having issues with deactivation but also more of the problems, like open, low, or high circuits, as well as general control performance.
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What Are the Symptoms of a P3400 Code?
The P3400 code is generally very subtle, and the major symptom that most vehicles experience is simply that the check engine light will turn on. Because the problem is simply that the vehicle is not able to operate at its maximum efficiency, you usually won’t notice many symptoms. The most notable symptoms tend to be a loss of fuel efficiency and simply a generally worse engine performance.
What Are Some Causes of a P3400 Code?
The most common cause of the P3400 code is simply a low engine oil level or a problem causing poor oil pressure, such as clogged oil passageways. However, it’s also possible that there’s a defective cylinder deactivation solenoid or a problem with the cylinder deactivation solenoid harness, or another defective sensor, such as sensors for mass airflow, throttle position, or intake control manifold absolute pressure.
How Serious Is the P3400 Code?
The main reason that the P3400 code is serious is because it can lead to unnecessary wear and tear on your vehicle. Although the P3400 code by itself isn’t extremely serious, it can increase engine emissions and reduce fuel economy, which can be very expensive. By fixing the problem as early as possible, you can actually save yourself money.
Can I Still Drive with a P3400 Code?
Because this code isn’t extremely serious, it’s common for you to be able to drive to the repair shop instead of needing to get a tow. However, experts will not recommend that you keep driving with this code active; it can cost you a lot of money in fuel and can make your vehicle drive a little more roughly than it usually would. It’s best to look into fixing the problem as soon as possible.
How Easy Is It to Diagnose a P3400 Code?
If the problem with the P3400 code is that your oil level is low, then you may be able to diagnose the problem at home. Many people are able to DIY an oil system fix. However, if the problem is anything else, the diagnosis process may be much more difficult. Many of the pieces that could be defective after checking oil are buried deeply in the engine, which means that the diagnosis process is often difficult past there.
How Difficult Is It to Inspect a P3400 Code?
The inspection process for the P3400 code often depends on the underlying cause of the problem. As indicated before, if the problem lies with the oil system, you’ll likely be fine to fix it on your own, but if the problem is outside of that system, you should likely talk to an expert. The inspection process can be very difficult because these systems are often very sensitive and buried deep in your engine, as well as the fact that what works for one make and model likely won’t work for another, which can be difficult to manage as a DIYer.
Need Additional Help with Your P3400 Code?
If you’re able to fix the P3400 code with your oil system, then you might be able to get your vehicle back on the road in no time. However, if this doesn’t fix the problem, it’s more likely that you’ll need to dig around in your vehicle and find the part that’s malfunctioning, then replace it. This is one of the reasons an expert can be a great option for this code.
With Kelley, you can find a repair shop in your area that will help you fix the problem overall. No matter what vehicle make or model you have, an expert can check the most common areas of trouble and help you fix them.
Additionally, this is a code that almost always comes with more OBD codes. If you’re experiencing this code, then check out the KBB OBD-II database to learn more about the other codes you may have seen.
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