Diesel Particulate Filter Warning Light Comes On
Modern diesel engines are equipped with an exhaust system that includes a diesel particulate filter. But a failing DPF will cause a warning light to come on and limit performance. If the vehicle is constantly ignored, it may switch into emergency mode or turn off completely.
What is a Diesel Particulate Filter? Diesel particulate filters are special aftertreatment devices that capture particles that are produced as a byproduct of diesel combustion. These particles usually appear in the form of soot or ash. Before the introduction of DPF technology, these particles were released into the environment through the truck’s exhaust.
The internal construction of a diesel particulate filter consists of a durable ceramic substrate formed into a dense honeycomb pattern. This honeycomb pattern effectively traps particles and prevents them from passing through the exhaust system entirely.
Over time, your vehicle’s DPF becomes clogged with soot and requires regeneration or automatic cleaning. The regeneration process is typically performed according to the requirements of the engine’s ECM/PCM and occurs without driver intervention. It occurs in different phases called active and passive regeneration.
Why does the DPF light come on?
The Diesel Particulate Light comes on to inform the driver that the engine’s passive regeneration has failed and an active regeneration is required. The DPF uses a series of pressure differential switches and backpressure sensors to measure the amount of soot buildup. The vehicle’s DPF warning light will illuminate when the amount of soot reaches a dangerous level.
The vehicle must also be driven continuously at highway speeds for up to 45 minutes for regeneration to begin at this level. A delayed stop while driving will interrupt the active regeneration process and often produces unsatisfactory results.
Most vehicles also display an alternate version of the DPF warning light just before the truck reduces power or goes into limp mode. Some vehicles, such as Duramax-equipped Chevy trucks, also display a warning in the built-in message center. Once this critical point of soot exposure is reached, there is little a driver can do without taking the vehicle to an authorized service center.
Is it okay to continue driving when the DPF light comes on? In most cases, you can continue driving even if your vehicle’s DPF warning light is on. In fact, most manufacturers recommend continuing to drive on the highway when the warning light is on, as your vehicle will be forced to go into an active regeneration cycle.
However, if your vehicle’s DPF warning light starts to flash or changes color from yellow to red, you should drive to a safe location as soon as possible. This generally indicates that your vehicle will experience a significant decrease in performance or a shutdown.
Moreover, many secondary problems can occur when trying to clean your vehicle’s DPF. In fact, improper cleaning methods and the use of unapproved chemicals can cause further damage to your DPF filter. Similarly, most manufacturers will disable a vehicle’s exhaust aftertreatment system if it is tampered with by anyone other than a certified technician.
How long will the filter last? The exact lifespan of a diesel particulate filter depends on a variety of factors. The most important of these factors is the driving style most frequently used, how often the vehicle is maintained, and general maintenance and cleaning of the DPF filter at set intervals. However, most diesel particulate filters can last at least 100,000 miles with very few issues.
What is a DPF Delete Kit? (Should I buy one?)
As the name suggests, a DPF delete kit is used to delete a vehicle’s factory DPF and often additional aftertreatment components as well. However, the actual scope of such kits varies significantly depending on the manufacturer and availability.
Installing a DPF delete kit typically requires entering custom settings into the vehicle’s ECM/PCM. This is because the vehicle’s operating software must be tricked into overlooking various sensors used by the aftertreatment system when removing the factory DPF. Failure to do so can result in a number of drivability-related issues. Thus, fines can be expected if the installation of such equipment is observed by federal officials.
For this reason, many auto repair shops today refuse to install any kind of DPF removal kit to avoid unnecessary liability risks. Additionally, there are far fewer DPF removal kits on the market today than there used to be. The kits that are still available on the market are sold for “off-road use” only.
