The diesel engine is using Diesel Particulate Filters (DPFs) to reduce emission since 2007. From time to time, you have to start regen to bring soot level down. There are two types of regen: Passive and Active Regen. Some of diesel engine only has passive regen and some of them only has active regen. Passive regen :while you are driving down the road through heat built indirectly in the system to make regen to bring soot down. Active regen, some time called parked regen, or service regen. The FCAR truck scanners will be able to triger passive regen and start force regen.
However, sometimes you can see the regen failed or condition are not matched. The reason for regen failed is all OEM to have certain protection for the engine. If the conditions are not satisfied, the forced regen will not be able to start. We will explain the flowing conditions:
1) Pysical part failed
Before DPF regen, the first thing first is to read engine and aftertream fault codes, if the code are showing any possible physical part or sensor damaged, you have to replace or repair them.
2) Dash buttons
Before DPF regen, the engine or aftertreament system have to check if the vehicle under safe positon. The following conditions must be met to initiate regeneration:
- Parking brake is engaged
- Clutch is not pressed in
- Accelerator pedal is not pressed in
- Vehicle is in neutral
- Vehicle speed is zero
Once you’ve confirmed these qualifications, check FCAR scanner to view the live data to ensure that a faulty clutch switch or accelerator pedal is not showing the electronic control module (ECM) they’re engaged when they’re not.
3) PTO & Idle Switches are ON
Check the PTO and idle switches in the dash. If they are ON,you must be turned off manually. Sometimes you need our scanner to disable PTO, ie. Thomas Bus with Cummins engine, you have to go Cummins engine system under special functions to temp disable Cab PTO.
4) Air condition is OFF and Engine temperature
This doesn’t apply to all engines, For Internation engine, you have to run engine until temperature over 146F
5) Derate Codes are Present
Once the active derate code is showing or under derate, the forced regen will fail in most case. You must read the derate code very carefully to understand the issue and possible to replace sensor or aftertreament. When the physical issue had been fixed, then you need to use FCAR scanner to go Advanced ECM data to reset or calibration in order to erase the derate code, so call hardcodes.
6) Soot Level
Some manufacturers and engines require the soot level to be above a certain percentage for a forced regeneration. The FCAR scanner will tell you regen is not needed. If your soot level is too high, the forced regen will fail too. Then it will need to reset soot level before run again regen.
7) Other Fault Codes
Your truck engine ECM is built to protect the engine. Many fault codes, when active, will not allow you to perform a regen. This is another common cause for a DPF regen failing. We highly recommend you check all your active fault codes under engine, aftertreament or other ECM. The FCAR scanner does have great coverage for all of these.