When the regeneration (regen) light flashes on a diesel-powered commercial vehicle, it signals the active cleaning of the vehicle’s diesel particulate filter (DPF). This process involves reduced power output, increased fuel consumption, and a time limit for driving.
Reduced Power and Increased Fuel Consumption: The regen process limits exhaust heat by reducing power output. Consequently, the engine consumes more fuel to generate the necessary heat for DPF cleaning.
Time Limit: Generally, you can drive for a short duration (15-30 minutes) with the regen light flashing. However, it’s crucial to take appropriate steps to minimize potential issues.
Steps When Regen Light Flashes
Find a Safe Location: Pull over to a safe spot and park the vehicle idle. Avoid parking on the side of a busy road.
Idle or Drive Slowly: Allow the vehicle to idle or drive at low speeds. This helps maintain the optimal exhaust temperature for proper DPF regeneration.
Monitor Regen Progress: Keep an eye on the regen light. It should turn off once the DPF cleaning process completes.
Avoid Excessive Force: Avoid hard braking or acceleration. These actions can interrupt the regeneration cycle, potentially leading to problems.
Consequences of Ignoring Regen Light
Disregarding the regen light can have severe consequences:
DPF Damage: Prolonged driving with the regen light flashing can overheat and damage the DPF, rendering it less effective or requiring costly repairs.
Engine Damage: An overheated and clogged DPF can potentially damage the engine, resulting in reduced performance and expensive repairs.
Increased Emissions: An uncleaned DPF leads to increased particulate matter emissions, violating environmental regulations and potentially leading to fines.
Vehicle Shutdown: Persistent failure to address the regen light may result in the vehicle shutting down as a self-protective measure.
Caution and Maintenance
Caution when Regen Light Flashes: Be cautious when the regen light flashes and follow the recommended steps to minimize risks.
Regular Maintenance: Regular vehicle maintenance, including timely oil changes and diesel fuel treatments, helps prevent DPF clogging and reduces the frequency of regeneration cycles.
Diesel Particulate Filter (DPF)
DPF Function and Illumination: The DPF is a vital component in diesel vehicles, removing harmful particles from exhaust gas. When the DPF light illuminates, it indicates the filter is becoming clogged and needs attention.
Causes of DPF Illumination:
Frequent short-distance driving or low speeds, hindering DPF regeneration
Faulty DPF pressure sensor
Poor vehicle maintenance
Consequences of Driving with DPF Light On:
Reduced fuel efficiency
Decreased performance
Potential engine damage
MOT failure
Recommended Action:
Attempt DPF regeneration by driving at sustained speeds (40 mph for 10 minutes)
If light persists or recurs, consult a mechanic for a forced regeneration, cleaning, or filter replacement
Prevention Tips:
Regularly drive at highway speeds for prolonged periods
Maintain regular vehicle servicing
Promptly address the DPF light to prevent costly repairs and environmental harm
FAQs on Driving with Regen Light On
How long can you drive with the regen light on?
With the regen light flashing, you can typically drive for a short period, usually 15-30 minutes, as the vehicle’s diesel particulate filter (DPF) actively cleans itself.
