9.4 Control of diesel particulate filter (DPF) system
The engine ECU determines the PM accumulation status from information from each sensor and sets regeneration or
cleaning level and timing.
1. Automatic active regeneration
When the PM level reaches 1, the engine ECU performs regeneration control to burn the PM that has been
accumulated.
If the DOC temperature (value of exhaust gas temperature sensor T
0
) is 250
℃
(482
℉
) or higher, the engine ECU
gives instruction to the injector to perform post injection.
Unburned fuel is combusted in the DOC raising the exhaust gas temperature to 550
℃
(1022
℉
) or higher and
combusting the PM in the DPF.
If the DOC temperature is less than 250
℃
(482
℉
), the fuel will not burn even if a post injection is performed so
post injection is not performed.
Therefore, regeneration is also not performed.
If the DOC temperature is 550
℃
(1022
℉
) or higher, the PM combusts on its own so post injection is not
performed (Passive regeneration state).
In addition, if auto regeneration is not completed within specified time while in PM level 2 state, the engine ECU
requests parked regeneration.
2. Parked active regeneration
When the PM level reaches 3, the engine ECU sends a warning to the machine on which it is equipped to perform
parked regeneration and commands output restriction.
During parked regeneration, pre-programmed operation processes are performed automatically.
As a preparation step for regeneration, first the intake throttle valve is operated reducing the amount of intake air
raising the exhaust gas temperature.
Further, engine speed is raised and adjusted so that the DOC temperature rises to 250
℃
(482
℉
) or higher.
After the DOC reaches 250
℃
(482
℉
) or higher, control is performed the same as for auto regeneration.
When regeneration is finished, the operation state is returned what it was prior to auto regeneration (idle speed).
3. Forced regeneration
When the PM level reaches 4, forced regeneration has to be performed using a failure diagnostics tool
(Diagmaster).
Regeneration control itself is the same as that for parked regeneration.
PM warning level
Regeneration method
Regeneration status
Control
Automatic active
regeneration
Parked active re-
generation
Regeneration
with service
tools
0
Not necessary
×
×
○
Not necessary regeneration.
－
1
Automatic active
regeneration
○
×
○
When the warning level
reaches 1, regeneration is
started automatically.
1.
If the DOC temperature
(value of exhaust sen-
sor T
0
) is 250
℃
(482
℉
) or higher, the
engine ECU gives in-
struction to the injector
to perform post injec-
tion.
2.
Unburned fuel is com-
busted in the DOC rais-
ing the exhaust gas
temperature to 550
℃
(1022
℉
) or higher and
combusting the PM in
the DPF.
3.
If the DOC temperature
is less than 250
℃
(482
℉
), the fuel will not
burn even if a post in-
jection is performed so
post injection is not per-
formed. Therefore, re-
generation is also not
performed.
(Continued)
4. ENGINE
MECHANISM
9. Aftertreatment system
4-76
D1803-CR-E4,D1803-CR-TE4,D1803-CR-TIE4,V2403-CR-E4,V2403-CR-TE4,V2403-CR-TE4BG,V2403-CR-TIE4
KiSC issued 12, 2018 A
Summary of Contents for D1803-CR-E4
Page 17: ...1 SAFETY KiSC issued 12 2018 A ...
Page 24: ...2 GENERAL KiSC issued 12 2018 A ...
Page 67: ...3 MAINTENANCE KiSC issued 12 2018 A ...
Page 100: ...4 ENGINE KiSC issued 12 2018 A ...
