EMISSION CONTROL SYSTEM
Diesel Exhaust System: Oxidation Catalyst And Diesel Particulate Filter System (If Equipped) Your vehicle is equipped with a diesel particulate filter. The diesel particulate filter is an inline filter in the exhaust system that reduces carbon emissions by trapping exhaust particles before they reach the tailpipe. The diesel particulate filter looks similar to a traditional exhaust catalyst, except larger, and is part of the exhaust system under the vehicle. The filter couples to a diesel oxidation catalyst that reduces the amount of harmful exhaust emitted from the tailpipe. As soot gathers in the system, it begins to restrict the filter. You need to periodically clean the soot that gathers inside the filter.
You can clean the soot in two different ways, passive regeneration and active regeneration. Both methods occur automatically and require no actions from the driver. During either one of these regeneration methods, you may notice a change in exhaust tone. At certain times, the information display will display various messages related to the diesel particulate filter. See the Information Displays chapter in the Owner Guide for more information. Passive regeneration In passive regeneration, the exhaust system temperature and constituents automatically clean the filter, or reduce the soot level, by burning (oxidizing) the soot. Cleaning occurs naturally because of normal engine operating conditions (at varying levels, due to driving patterns).
Diesel particulate filter maintenance
You must properly maintain your diesel particulate filter in order for it to function properly. Do not disregard the
EXHAUST OVERLOADED DRIVE TO CLEAN and EXHAUST AT LIMIT DRIVE TO CLEAN NOW maintenance messages otherwise system damage could result that your warranty may not cover. Failure to perform active or Operator Commanded Regeneration when instructed could result in a clogged diesel particulate filter. If your diesel particulate filter fills beyond the regeneration threshold, your vehicle will disable the ability for active and Operator Commanded Regeneration. This could result in irreversible damage to the filter requiring replacement that your warranty may not cover. If your vehicle is not equipped with Operator Commanded Regeneration, check with your dealer for availability. Once the diesel particulate filter is full of exhaust particles, the engine control module will command the exhaust system to clean the filter through a process called active regeneration. Active regeneration requires the engine computer to raise the exhaust temperature to eliminate the particles. During cleaning, the particles convert to harmless gasses. Once cleaned the diesel particulate filter will then be ready to continue trapping exhaust particles. The regeneration process operates more efficiently when you safely operate your vehicle at least 30 mph (48 km/h) with a steady pedal for approximately 20 minutes to complete the process. The frequency and duration of regeneration will fluctuate by how you drive your vehicle, outside air temperature, and altitude. For most driving, regeneration frequency will vary from 100- 500 miles (161 - 805 km) between occurrences and each occurrence will last from 9 - 20 minutes. You can usually reduce the duration of regeneration if you maintain a constant speed above 30 mph (48 km/h). When the engine control module detects that the diesel particulate filter is nearly full of particulates and you are not operating your in a manner to allow effective automatic cleaning, the information display will display EXH OVERLOADED DRIVE TO CLEAN for base information display and Exhaust Overloaded Drive to Clean for the optional information display. These messages appear as a reminder for you to drive in order to clean the diesel particulate filter. If you operate your vehicle in a manner to allow effective automatic cleaning, the information display will display a cleaning exhaust filter message, which is the normal regeneration process. See the Information Displays chapter of the Owner Guide for more information. You can also choose Operator Commanded Regeneration to clean the exhaust system at this point. See How to start Operator Commanded Regeneration later in this chapter. If you are not able to drive in a manner that allows effective automatic cleaning (active regeneration) or you choose to perform regeneration of the diesel particulate filter (cleaning) while at idle (stationary), then Operator Commanded Regeneration would need to be performed. See Operator Commanded Regeneration later in this chapter.
Mine flashes a momentary message "Cleaning Exhaust" when beginning the passive cycle...
But... when the DRIVE TO CLEAN message comes on it will stay until it finishes or you cut the motor off...