What Is the P0604 Code?
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The P0604 code indicates an issue with the random access memory (RAM) in the powertrain control module (PCM). The PCM is a type of computer in the vehicle that has to maintain memory to understand what’s going on in the various modules of your engine. As with any computer, it has certain information that it keeps readily available and certain information that may take slightly longer to access. The RAM helps the PCM access information that needs to be readily accessible, responding to information requests rapidly. This error indicates an issue with that memory.
More About the P0604 Code
There is a lot of information coded into the PCM, so much information that it would be nearly impossible for all information to be accessed immediately when desired. That’s why certain information is stored in the RAM, and certain information is stored elsewhere. The precise pieces of information stored in the RAM may vary from vehicle to vehicle, and even individual drivers will end up with unique RAM storage. This error is fairly generic but can indicate any issue with the vehicle’s access to RAM information.
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What Are the Symptoms of a P0604 Code?
The exact symptoms you’ll see due to a P0604 code depends on the type of information that the PCM is having a hard time gathering. The code may seem as benign as a check engine light turning on, or it may be as severe as a complete no-start condition. The more RAM information that is difficult for the vehicle to access, the more likely it is that you’ll have severe drivability issues, up to and including being completely unable to start your vehicle.
What Are Some Causes of a P0604 Code?
There are many possible causes of the P0604 code. An issue with the PCM fuse can cause the P0604 code, as can any issues with the battery terminal connection, power supply circuit wiring, or battery voltage, although low battery voltage will generally cause other problems as well. There can also be issues with the programming or with alternate PCM programs. Finally, in some situations, the issue may lie with the PCM itself, which you may need to replace, although this is rare.
How Serious Is the P0604 Code?
The P0604 code is very serious. As already mentioned, this can sometimes cause a complete no-start condition, which will be an issue that you obviously need to fix as soon as possible. However, even if the condition allows you to drive, you don’t want to be driving when the RAM in your vehicle is malfunctioning. It can cause all sorts of problems on the road, oftentimes without warning, which can lead to severe dangers when driving. You definitely want someone to check out this code if it appears.
Can I Still Drive with a P0604 Code?
In some cases, you won’t be able to drive with the P0604 code active. However, even if the code allows you to drive, you shouldn’t just continue to drive with this code active. You shouldn’t drive even if it seems like there are no drivability issues with this code. You never know when an issue with the RAM will result in serious drivability problems, sometimes even without warning.
How Easy Is It to Diagnose a P0604 Code?
This diagnostic process is often difficult for a P0604 code. This is because there are so many different possible causes, as well as because the PCM’s memory board isn’t a location where you often see issues. Most DIYers won’t have the knowledge necessary to diagnose the actual cause of a P0604 code, which is why many people choose to get help instead.
How Difficult Is It to Inspect a P0604 Code?
The inspection process for a P0604 code can be as difficult as the diagnostic process, largely because many people don’t know how to inspect electronic components within a vehicle. Much of the process of fixing a vehicle has to do with the engine and other physical components rather than the onboard computer. If you’re worried about the computer, which includes the PCM, ECM, and other onboard electronic components, then it might be a good idea to get help from an expert.
Need Additional Help with Your P0604 Code?
Most DIYers and car repair hobbyists will end up needing help with the P0604 code. If you’re looking for help with your vehicle’s P0604 code, then you can talk to an expert to see what the problem is and how you can fix it.
Start with using KBB to find a repair shop in your area. This service center locator will help you find the closest location to you.
This code also tends to come with other codes, especially if the problem is something like a low battery. You can check out the meaning of these other codes using the KBB OBD-II database.
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