What Is the P0390 Code?
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The definition of code P0390 is “Camshaft Position Sensor B Circuit Bank 2,” although some manufacturers will refer to it as just “Camshaft Position Sensor B Circuit” or even simply “Camshaft Position Sensor.” The definition of code P0394 is “Camshaft Position Sensor B Circuit Intermittent Bank 2.” These codes indicate that the powertrain control module (PCM) or engine control module (ECM) has detected a problem with the camshaft position sensor circuit in Bank 2. As a generic powertrain code, you can find the P0390 code in just about any OBD-II-equipped vehicle.
You may also be interested in P0340 Camshaft Position Sensor “A” Circuit.
More About Error Code P0390
Your camshaft, also called a “cam,” is a critical part of your internal combustion engine. The cam lobes, which are part of the camshaft, are usually positioned right above the cylinder banks, allowing them to control the valves and precisely manage fuel injection and the air/fuel mixture entering the chamber, helping with precise ignition timing. As you might expect, the timing of the camshaft is critically important to make proper calculations. If your vehicle can’t time these rapid movements correctly, the ignition can be completely thrown off. The P0390 or P0394 fault code indicates that part of the circuit handling the camshaft position sensor (CMP sensor) B Bank 2 circuit is not functioning properly.
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What Are the Symptoms of a P0390 Code?
Your camshaft is a necessary part of your vehicle’s function, which means that the cam sensor issues inherent in the P0390 or P0394 fault code can come with various extremely serious symptoms. Most notably, you’ll often see common symptoms like decreased engine performance, lack of power, timing issues, general fuel delivery problems, and even issues with the engine not starting. If the engine can start, you will likely see reduced fuel economy, as the vehicle may not be able to monitor fuel consumption as easily. Rough running and even misfiring can also occur with DTC P0390 or P0394. The check engine light or other malfunction indicator lamp should also turn on.
What Are Some Causes of a P0390 Code?
The name of DTC P0390 or P0394 generally lets you know the problem. There’s an issue in the camshaft position Sensor B, Bank 2 circuit. That may mean the camshaft position sensor has failed, an issue with a wire or connector within the circuit, or even an open circuit surrounding the camshaft position sensor. Issues with the variable valve timing system can also cause this problem. Even issues associated with the timing chain and related components can cause the P0390 or P0394 code, although they frequently create other codes. Aftermarket kit products also frequently result in this problem, as they may create a loose sensor situation.
How Serious Is the P0390 Code?
The P0390 or P0394 code should be treated as serious. In some cases, the P0390 code will make it so that you can’t even drive at all, as it could make it difficult for you to start the car. Because this code only points to a single camshaft position sensor, your vehicle may be able to adjust based on other sensors, but it’s still best to get the sensor fixed as soon as possible. Avoiding engine damage or loss of engine power is worth being proactive with what might be a bad camshaft position sensor or some other mechanical issue.
Can I Still Drive with a P0390 Code?
It depends on the symptoms you’re experiencing. In most cases, you will still be able to drive, although you may experience issues with engine performance overall. In some cases, you physically won’t be able to drive because your vehicle won’t be able to start. However, even if you can drive, you should still avoid doing so, as driving with a potentially dangerous engine issue, such as a problem with the camshaft or crankshaft, can negatively affect your engine in the long run. Plus, if you’re dealing with poor fuel economy or fluid leaks, running the vehicle under conditions that include powertrain control module codes might cost you more money.
How Easy Is It to Diagnose a P0390 Code?
Diagnostic steps associated with the P0390 diagnostic trouble code aren’t always easy. As indicated earlier, these fault codes mean there’s a problem with the circuit associated with the camshaft position Sensor B in Bank 2, but that problem can be anywhere within that circuit. It doesn’t have to be a problem with the actual sensor. Whether that means the sensor itself has failed, there’s a short in the wiring, or there’s a problem with an associated system, you still need to determine where the problem is within the system. If you’re worried about being able to check the sensor for signs of damage, identify a bad camshaft sensor, or even just determine a broken wire, talk to a professional mechanic instead.
How Difficult Is It to Inspect a P0390 Code?
The inspection process for the P0390 OBD-II trouble code is also quite difficult, as this system is one of the core components within your engine. It’s common to have difficulty getting to the camshaft position sensor. Plus, when inspecting the sensor fault, you’ll need a reliable vehicle information source, such as repair guides, technical service bulletins, and wiring diagrams. If you don’t have this information for the sensor in question or don’t want to go further into the engine, talk to a certified mechanic instead.
Need Additional Help with Your P0390 Code?
Getting extra help with the P0390 or P0394 code is how most DIYers handle this issue. Whether you’re dealing with a camshaft sensor malfunction, issues with control systems, or even broken wiring and electrical connection problems, plenty of people can help you find repair procedures that work for you with no need for a follow-up repair.
First, find an auto repair shop in your area. A local auto repair shop will help you with your repair without making the common mistakes that often plague DIYers.
This code also frequently comes with additional codes. If you see other codes on your scan tool, check out the OBD-II database at KBB.com to learn more about them and how to fix them.
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