What Is the P2459 Code?
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The definition of code P2459 is “Particulate Filter Regeneration Frequency Bank 1,” also defined as “Diesel Particulate Filter Regeneration Frequency” by some engines. This code means that the powertrain control module (PCM) or engine control module (ECM) has detected a problem with the regeneration process for your diesel particulate filter. It is a generic trouble code and may turn up in various vehicles but will only occur in vehicles with a diesel engine.
More About Error Code P2459
The emissions from a diesel engine are naturally much higher than those from a gasoline engine, which is why diesel engines use diesel exhaust fluid (DEF) to convert leftover exhaust particles to non-harmful gases. To do this, the engine injects DEF fluid and reductant catalyst (SRC) into the exhaust stream, bringing the diesel particulate filter (DPF) up to temperature and converting NOx to nitrogen, carbon dioxide, and water, a process called “regeneration.” This process needs to occur regularly. This code indicates that the DPF has not regenerated with the correct degree of regularity over a specific period of time.
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What Are the Symptoms of a P2459 Code?
Even though it may not seem like the P2459 code is especially serious, DPF regeneration is critical to maintaining exhaust back pressure. Your symptoms may include excessive black smoke from the exhaust, an inability to maintain the correct RPM, an increased engine temperature, and overheating in the DPR housing or other exhaust components. Excessive black smoke usually comes from excess soot particles on the filter. Larger soot particles are burned off the filter during regeneration, and if this cleaning process isn’t completed, it’ll produce black exhaust. Other DPF codes will also frequently accompany this one. The check engine light should also turn on.
What Are Some Causes of a P2459 Code?
The P2459 code can happen in some vehicles simply due to too many short trips in your diesel vehicle and not enough long ones, as DPF regeneration usually occurs when cruising on the highway. However, if there is an underlying cause where something is actively wrong, it may include any of these:
- Defective DPF pressure sensor
- Faulty exhaust pressure sensor
- Insufficient diesel exhaust fluid
- Incorrect diesel exhaust fluid
- Shorted or open wiring for the DPF injection system
- General DPF failure
- Need for a manual regeneration cycle
- Faulty PCM or PCM programming error
Any of these problems can result in the P2459 code. Regardless of which is causing your P2459 code, finding and fixing the issue is extremely important.
How Serious Is the P2459 Code?
The P2459 code is surprisingly serious. DPF regeneration keeps your vehicle’s exhaust back pressure at an optimal level, which can result in serious drivability issues if you can’t maintain it. On top of that, you also won’t be able to pass an emissions test if this code is active. You might also run into overheating problems if the vehicle maintains these issues. Fix this code as soon as possible for the best results.
Can I Still Drive with a P2459 Code?
You can usually still drive when the P2459 code is active, but most experts will recommend that you don’t. The P2459 code is a code that usually won’t actively impact your drivability, but it will wear down your engine health over time. The more you drive, the more likely you’ll run into a serious vehicle issue, and that’s why it’s best to avoid driving when the P2459 code is active. Get help from a certified mechanic instead to avoid permanent damage.
How Easy Is It to Diagnose a P2459 Code?
It depends on the underlying cause. The two easiest problems to diagnose are low diesel exhaust fluid and the need to run the regeneration process manually. You can fix these problems with very little knowledge of the vehicle. However, if you’re experiencing a problem with electrical connections and wiring or if one of the parts of the regeneration system is broken, you’ll need to be able to determine the problem and how to fix it. A professional mechanic can help you fix your DPF pressure sensor code more effectively without requiring follow-up repairs.
How Difficult Is It to Inspect a P2459 Code?
Inspection, as with diagnosis, is often difficult. To inspect many components of this system, you’ll need tools like a digital volt/ohmmeter (DVOM), a diagnostic code scanner, and a source of vehicle information, like technical service bulletins, wiring diagrams, vehicle service manuals, and repair guides. You’ll also need to know where the most common problems are, how to check for them, and how to check for less common issues. If you’re not exceptionally well-versed in this inspection process, it’s best to get help from an expert.
Need Additional Help with Your P2459 Code?
The P2459 generic powertrain code often requires additional help, so if you’ve decided to hand the problem over to an expert, there’s no need to worry.
For many people, the first step is to find an auto repair shop in your area. When you find a local auto repair shop, it’s easier to get assistance without going too far out of your way.
This code also frequently results in additional codes. To get help with these codes, check out the OBD-II database at KBB.com, where you’ll find information and definitions for other error codes.
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