What Does The P2002 Code Mean?


Diesel engines use a similar system to announce faults as a gas-powered motor. Your diesel vehicle is still equipped with an OBD-II system that lets you look at trouble codes. If you see the P2002 code on your scanner, you may wonder what the problem is.

In this guide, we cover the meaning of the P2002 while also looking at the causes and the symptoms. By the end of the article, you should know how to troubleshoot and fix the fault for a smoother ride. 

Code P2002 Definition

P2002 – Diesel Particulate Filter Efficiency Below Threshold Bank 1

What Does the P2002 Code Mean?

The P2002 trouble code is generic among diesel-powered vehicles. It won’t show up with a gas-powered engine. This DTC indicates that the ECM detected an issue with the particulate exhaust filter. The problem occurs with the Bank 1 set of cylinders.

This trouble code indicates that there’s been a change in the back pressure. It’s beyond what the manufacturer specifies is normal with the diesel particulate filter, so the code is set until the problem is repaired. 

What Are The Symptoms Of P2002?

For some drivers, the only symptom experienced is the Check Engine Light. Beyond that, you may notice some performance issues or trouble with the fuel economy.

Here are some of the top complaints. 

What Are The Causes of P2002?

It’s clear that the problem has to do with the diesel particulate filter (DPF). However, the exact cause of the problem can vary. 

Here are a few of the most common causes.

  • Driving too slow keeps soot from burning properly in the DPF.
  • Bad diesel fuel, with too much sulfur that clogs the DPF
  • Bad DPF differential pressure sensor
  • Damaged hoses between DPF pressure sensor and filter
  • Damaged DPF
  • Air leak before the DPF
  • Dirty air cleaner
  • Defective ECU
  • Malfunctioning aftermarket parts
Diesel Particulate Filter

How Serious is the P2002 Code?

Medium – You don’t necessarily need to stop driving right away. You should be able to get your vehicle home or to the nearest shop without too many problems. 

However, you don’t want to continue running it this way as the vehicle could go into limp mode. While in this mode, the ECM controls the top speed and harnesses power to protect the drivetrain. The only way to turn off limp mode is to fix the problem that’s caused the light to come on. 

How Do I Fix the P2002 Code?

There are many ways to fix the P2002 code, but none of the solutions work unless it resolves the problem that your vehicle is facing. For that reason, we must recommend a complete diagnosis before trying to repair anything. We’ve outlined those steps below.

However, here are a few of the most common repairs. 

  • Clean the diesel particulate filter 
  • Change the diesel particulate filter
  • Replace DPF differential pressure sensor
  • Replace hoses between DPF sensor and filter
  • Replace diesel fuel
  • Repair air leak
  • Reprogram/replace ECM

Common P2002 Diagnosis Mistakes

car diagnostics

Many people don’t realize how much of an impact poor-quality fuel can make on the diesel system. If the tank was filled with bad diesel fuel, it could clog the filter.

If you think the cause was the fuel, try running the vehicle at highway speeds before making any repairs. This step might be enough to clean out the contaminants, so you can save some money. It’s also wise to use more caution about where you get your fuel so this problem doesn’t reoccur. 

You also want to inspect the DPF differential pressure sensor and the hoses between the DPF filter and the sensor. Then you should start a DPF filter regeneration.

How to Diagnose the P2002 Trouble Code?

If you are mechanically inclined, you may be able to figure out the problem causing the P2002 trouble code. With some simple tools and a little know-how, the issue can be found and repaired. 

Here are the steps that professional mechanics use.

  1. Read your vehicle’s service manual or research any related bulletins.
  2. Read the trouble codes with your OBD-II scanner. The OBD2 codes reveal what’s going on with the system and can be used as puzzle pieces to pinpoint the problem. We recommend researching them in our trouble code library
  3. Check and diagnose the DPF differential pressure sensor.
  4. Check the hoses between the DPF differential pressure sensor and the DPF filter, and replace if necessary.
  5. Perform a DPF filter regeneration with a compatible scan tool or with the car’s automatic DPF filter regeneration.
  6. Remove any performance mods or aftermarket parts that were just installed, which may be hindering the exhaust.
  7. Clean or replace the diesel particulate filter.
  8. Check for air leaks and repair.

Beyond these steps, you may do better to hire a professional mechanic. Diagnosis and repair can become tricky from here on out. 

How Much Does It Cost To Fix Code P2002?

Once you’ve completed the diagnosis, you should know what needs to be replaced. Here are a few general ideas about the parts and labor cost for each repair. Keep in mind if you can repair the vehicle on your own, you should pay much less. 

  • Clean the diesel particulate filter – $25-$75
  • Change the diesel particulate filter – $750-$3,000
  • Replace diesel fuel – $200-$750
  • Replace differential pressure sensor – $150-$400
  • Repair air leak – $50-$550
  • Reprogram/replace ECM – $250-$2,500

A Mechanic’s Tips About The P2002 Code

Any time the diesel particulate filter fails to regenerate, the engine management system attempts to increase the exhaust temperature. This system operation is critical to burning off any soot that builds up in the DPF. 

However, this operation causes the engine to work harder and it will burn more fuel in the meantime. Not only that, but the increase in engine activity leads to premature wear of the motor. For these reasons alone, it’s important to resolve the situation as quickly as possible. 

Is code P2002 serious?

It depends. You may have a quick fix, such as cleaning out the DPF. On the other hand, there could be something more serious going on, such as a defective sensor or an air leak. The only way to know for sure is to diagnose the fault. However, if the DPF filter is clogged, it could cause the engine to stall.

How do I fix the error code P2002?

The first step is to diagnose the problem. Check the other trouble codes and figure out where the malfunction is. You may need to clean the DPF, replace a bad differential pressure sensor or repair an air leak. The vehicle’s service manual should help you figure out what to do next. 

Can you drive with the P2002 code?

You may be able to drive a short distance once the P2002 code sets in the system. It’s likely you will be able to drive home or to a local repair shop without any problem. However, the vehicle could go into limp mode to protect against engine wear, which would make it more difficult to drive. 

How do you clear a particulate filter?

There are a few ways to clean the particulate filter, you can either use a fuel additive in the fuel tank, or you can remove the filter and run it through a special particulate filter cleaning machine to clean it for the best result.

We are never fans of dealing with the P2002 trouble code because it can mean so many different things. If you have the patience and some experience, you’ll be able to hunt down the fault without too much stress.

Hopefully, you are dealing with a small issue that is easy to resolve. Either way, you want to repair the problem as soon as you can to ensure there’s no engine damage or wear.

Categories: OBD Codes

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