P242F - Diesel particulate filter restriction - ash accumulation

Code P242F will be set when the soot/ash levels in the exhaust particulate filter system exceed the maximum allowable level. The fix requires replacing the DPF.

OBD-II DTC Datasheet

P242F - Diesel particulate filter limitation - ash accumulation

What does code P242F mean?

This Diagnostic Trouble Code (DTC) is a generic transmission code, which means it applies to most new diesel vehicles (Ford, Mercedes Benz, Vauxhall, Mazda, Jeep, etc.). Although general, specific repair steps may differ depending on the brand / model.

On the rare occasion that I found a stored code P242F, it meant the powertrain control module (PCM) detected a DPF ash restriction level that is considered restrictive. This code is used exclusively in diesel vehicles.

The DPF looks like a muffler or catalytic converter, protected by a steel integrated exhaust shroud. It is located upstream of the catalytic converter and / or NOx trap. Large soot particles are trapped in the particulate filter. Penetration of small particles and other compounds (exhaust gases) is allowed.

The most important part of any DPF is the filter element. A DPF can be constructed using one of several elemental compounds that trap soot while still allowing engine exhaust to pass through. These include paper, metal fibers, ceramic fibers, silicone wall fibers and cordierite wall fibers. Cordierite is a type of ceramic-based filter compound and the most common type of fiber used in DPF filters. It is inexpensive to manufacture and has exceptional filtration characteristics.

When exhaust gases pass through the element, large soot particles are trapped between the fibers. When a sufficient amount of soot has accumulated, the exhaust pressure increases accordingly and the filter element needs to be regenerated to allow the exhaust exhaust gas to continue to pass through it.

Ash accumulation is a side effect of DPF filtration and regeneration. This is caused by the frequent use of non-flammable materials such as lubricant additives, trace elements in diesel fuel / additives, and debris from engine wear and corrosion. Ash usually accumulates along the walls of the DPF or in plugs near the rear of the filter element. This greatly reduces the efficiency of the filter element and dramatically reduces the soot accumulation and filter capacity.

Since ash is close to the walls and rear of the DPF, soot particles are pushed forward, effectively reducing the channel diameter and filter length. This can lead to an increase in the flow rate (through the DPF) and, as a consequence, to an increase in the voltage output of the DPF pressure sensor.

When the PCM detects these noticeable changes in DPF flow, speed or volume, a P242F code will be stored and a Malfunction Indicator Lamp (MIL) may illuminate.

Severity and symptoms

Conditions that cause a P242F code to persist can cause internal damage to the engine or fuel system and should be corrected as soon as possible.

Symptoms of a P242F code may include:

• Reduced engine performance
• Excessive black smoke from the exhaust pipe
• Strong diesel smell.
• Increased engine temperature
• Passive and active regeneration continue to falter.
• Higher transmission temperatures
• Fault indicator light "ON"
• Message center/instrument cluster labeled "Catalyst Full - Service Required"

Causes of error code P242F

Possible causes of this engine code include:

• Excessive ash accumulation in the particulate filter
• Defective DPF pressure sensor
• DPF pressure sensor tubes / hoses clogged
• Open or short circuit in the DPF pressure sensor circuit
• Ineffective DPF Regeneration
• Excessive use of engine and / or fuel system additives
• Exhaust Gas Temperature (EGT) Sensor Harness Open or Shorted
• Diesel particulate filter full of ash
• Incorrect Exhaust Gas Temperature (EGT)
• Exhaust gas temperature (EGT) sensor circuit poor electrical connection
• Mass Air Flow (MAF) / Intake Air Temperature (IAT) Sensor Malfunction

Error code P242F

Diagnostic and repair procedures

A good starting point is always to check the Technical Service Bulletins (TSB) for your particular vehicle. Your problem may be a known issue with a known manufacturer-released fix and could save you time and money while troubleshooting.

Diagnosing a P242F code will require a diagnostic scanner, digital volt / ohmmeter, and a reliable source of vehicle information (I'm using All Data DIY).

I would start diagnosing a stored P242F by visually inspecting the associated harnesses and connectors. I would focus on wiring near hot exhaust components and sharp edges (such as exhaust flaps). I like to connect the scanner to the car diagnostic connector and retrieve all stored codes and freeze frame data. Record this information for future reference. This can be useful if this code turns out to be intermittent. Then I reset the codes and test drive the car.

If the vehicle has been operated with excessive amounts of engine and fuel system additives, or if the DPF regeneration schedule has been ignored (passive DPF regeneration systems), suspect that ash build-up is the root of the condition for this code to persist. Most manufacturers (modern clean diesel vehicles) recommend a maintenance schedule for DPF ash removal. If the vehicle in question meets or is close to DPF ash removal mileage requirements, suspect ash accumulation is your problem. Consult your vehicle information source for DPF ash removal procedures.

If the code resets immediately, see your vehicle information source for instructions on how to test a DPF pressure sensor using the DVOM. If the sensor does not meet the manufacturer's resistance requirements, replace it.

If the sensor is OK, check the DPF pressure sensor supply hoses for blockages and / or breaks. Replace hoses if necessary. For replacement, high temperature silicone hoses must be used.

If the sensor is working properly and the power lines are good, begin testing the system circuits. Disconnect all associated control modules before testing circuit resistance and / or continuity with the DVOM. Repair or replace open or shorted circuits as necessary.

What is P242F Engine Code [Quick Guide]

Additional diagnostic notes:

• DPF ash removal intervals and procedures are critical to the effectiveness of the DPF.
• If the DPF pressure sensor hoses are melted or cracked, it may be necessary to re-route after replacement.
• Check your vehicle information source to find out if your vehicle is equipped with an active DPF regeneration system or a passive system.
• Clogged sensor ports and clogged sensor tubes are common

How to Fix P242F Diesel Particulate Filter Ash Buildup

Want to fix DTC P242F? Read these points mentioned below:

• Diesel particulate filter replacement
• Check for faulty sensors, circuit and wiring problems and repair immediately.
• Clean the diesel particulate filter properly
• PCM may need reprogramming

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What parts of the car should be repaired with error P242F

1. Engine control module . ECM errors are rare but can be a big problem as a faulty ECM will cause the vehicle to not operate properly and it can also cause incorrect OBD codes to be stored in the system which can also lead to misdiagnosis. Therefore, replace the failed ECM components now!
2. Electronic control unit - The ECU coordinates with the temperature sensor to control the fan to keep the battery temperature under control. So, replace the failed ECU components now!
3. transmission control module - Check for a PCM error that could be related to circuit faults that may require a complete replacement and reprogramming. Replace it now!
4. Diagnostic tool . High-quality diagnostic tools are needed to detect the error. Visit us today for amazing offers.
5. Diesel particulate filter The diesel particulate filter (DPF) is a filter that captures and stores exhaust soot (some call them soot traps) to reduce emissions from diesel vehicles. But because their capacity is limited, this trapped soot needs to be cleaned out or "burned off" periodically to regenerate the DPF. So replace it now

Vehicles displaying the P242F OBD code frequently

Error Code P242F Acura OBD	Error Code P242F Honda OBD	P242F Mitsubishi OBD Error Code
P242F Audi OBD Error Code	Error Code P242F Hyundai OBD	Error Code P242F Nissan OBD
P242F BMW OBD Error Code	P242F Infiniti OBD Error Code	P242F Porsche OBD Error Code
Error Code P242F Buick OBD	P242F Jaguar OBD Error Code	Error Code P242F Saab OBD
OBD Error Code P242F Cadillac	Jeep OBD Error Code P242F	Error Code P242F Scion OBD
Error Code P242F Chevrolet OBD	Error Code P242F Kia OBD	P242F Subaru OBD Error Code
Error Code P242F Chrysler OBD	Error Code P242F Lexus OBD	Error Code P242F Toyota OBD
OBD error code P242F Dodge	P242F Lincoln OBD Error Code	OBD Error Code P242F Vauxhall
Error Code P242F Ford OBD	Error Code P242F Mazda OBD	Error Code P242F Volkswagen OBD
Error Code P242F GMC OBD	Error Code P242F Mercedes OBD	Error Code P242F Volvo OBD

Simple Engine Error Diagnosis OBD Code P242F

Here are a few steps you must follow to diagnose this DTC:

• Start your diagnosis by visually inspecting the appropriate harnesses and connectors. Pay attention to wiring that is routed near hot exhaust system components and sharp edges (such as exhaust guards).
• Plug the scanner into the vehicle's diagnostic socket and extract all stored codes and freeze frame data. Record this information for future reference. This might be useful if this code turns out to be intermittent.
• Erase the codes and test the car. If the vehicle has been driven with excessive amounts of engine and fuel system additives, or if the DPF regeneration schedule has been ignored (passive DPF regeneration systems), suspect ash buildup is at the root of the condition for this code to be stored.
• Most manufacturers (of modern clean diesel vehicles) recommend a maintenance schedule for DPF ash removal. If the vehicle in question is at or close to DPF ash removal mileage, suspect ash buildup is your problem.
• Consult your vehicle source for DPF ash removal procedures. If the code clears immediately, contact your vehicle information source for instructions on checking the DPF pressure sensor with the DVOM.
• If the sensor does not meet the manufacturer's resistance specifications, replace it. If the sensor is OK, check the DPF pressure sensor supply hoses for blockages and/or breakage. Replace hoses as needed.
• High temperature silicone hoses must be used for replacement. If the sensor is working properly and the power lines are intact, begin testing the system circuits. Disable all relevant control modules before testing circuit resistance and/or continuity with the DVOM. Repair or replace open or shorted circuits as needed.

Common Mistakes When Diagnosing OBD Code P242F

1. Follow the manufacturer's DPF ash removal intervals and procedures, which are critical to the effectiveness of the DPF.
2. If the DPF pressure sensor hoses have melted or cracked, they may need to be rerouted after replacement.
3. Clean clogged sensor ports and clogged sensor tubes regularly.

How much does it cost to diagnose code P242F?

The cost of diagnosing code P242F is 1 hour of work. Auto repair diagnostic times and costs vary by location, vehicle make and model, and even your engine type. Most body shops charge between $30 and $150 an hour.